Introduction:
Phoenix is an "okay" agent. His ultimate allows him to effectively go first without the risk of dying, allowing his team to go forward. His wall works very well when played aggressively, as his blinds can go through them and surprise enemies from unexpected angles. Not only that, but he's able to heal himself if he survives his 1v1 if he still has his wall or molly.
Now going by these pros, he is a good agent and a good when playing with his team, however we haven't even gotten into his cons.
His wall is basically useless when compared to the likes of other walls. Every single wall ability in the game except for Sage's does not collide with projectiles, plus every other single wall in the game lasts longer than phoenixes. Neon's wall acts sort of like a projectile and spawns walls on both sides. Viper's wall is both extremely long and lasts way longer. For his molly, it does practically no damage and it automatically goes down after a short period of time, making it impossible for Phoenix to use if he's far away from the location he wants his molly to be. Not only that, but other abilities such as Brimstone's, Viper's, Sage's Slows (even though they don't do damage), Kayo's, and Raze's are all overall better than phoenix's. The only good thing about Phoenix's fireball is that he can also make the molly go down quickly if he wants and he can heal himself with it. His flashes are practically useless since there are so many other blinds that to better, such as Kayo's, Reyna's, Skye's, and ESPECIALLY Breach's.
Now, I'm going to try and come up with reworked abilities that also suit the style the devs intended Phoenix to be played.

How I think the devs intended phoenix to be played:
Looking at the first 10 agents in the game (Phoenix, Sova, Viper, Sage, Omen, Raze, Breach, Cypher, Brimstone, and Jett), Phoenix is one of the 3/10 agents that have blinds and 2/10 agents that can heal themselves. He's also 4/10 agents to have a damage-dealing molly. Going by this, his ultimate, and the 3 trailers he's starred in, I believe the devs intended Phoenix to be a very great agent to go first into battle, as well as a good agent that can make an area of denial-type of agent. His curving blinds allow him to specialize in peaking angles (which is great for going first, especially at a chokepoint) and his fireball should be used to stall time as seen in "Duelists". So now we know that Phoenix was made to have an aggressive playstyle on offense and an optional but viable passive on defense. Time to rework some of his abilities.

Reworked abilities:
Phoenix's Molly - The only good thing about Phoenix's molly is the fact that it can heal him, which is why most people use Phoenix's molly to, well, heal themselves especially when there's no healing agent. I think the ability to heal himself should stay, as it's going first usually means the first to take damage. The ability to heal himself rewards him for going first, as not only does he get a pick, but the damage the enemy dealt with him can be retrieved again without wasting a Skye's or Sage's heal, saving them for someone more important such as the Top-Frag, themselves, or an agent made for holding down site both on offense and defense. First of all, they should increase the time it takes until phoenix's molly goes straight down, allowing his mollies to go further. They should also keep the ability to immediately send the fireball down. Phoenix's fireball should last longer and have a larger area of effect. This would make his molly very important for delaying an enemy advance, both on defense and offense. This would then increase the amount of health phoenix gains, so to compensate, the healing rate should lower so that Phoenix still gets the same amount of health. It should also have afterburn to make it punish overconfident enemies that walk into it.

Phoenix's Wall - The wall is good when combined with other abilities, but Neon's and Viper's walls make Phoenix's wall look useless, mainly because Neon's wall has 2 of them and acts as a projectile (allowing the neon to make walls over colliding surfaces) and Viper's wall can extend from practically across the map and lasts longer. The only good thing about phoenix's wall is its ability to heal phoenix and curve. Going by Phoenix's first trailer, the wall should be used to allow his team to check 1 angle and not have to worry about the other. However, things such as Sova's recon arrow can completely stop this, and enemies can use Phoenix's wall offensively, such as throwing a blind through it. Here's how I would make it better. First of all, it should last longer. Compared to the likes of Neon's and Viper's walls, Phoenix's wall comes down too quickly. It shouldn't last longer than Neon's or viper's, just somewhere near that time. It could also sort of burn enemy projectiles. It could also be higher to prevent stuff like a Recon arrow being shot above it. This would also make Phoenix good at taking care of enemies peeking at high ground, overall making him better at going first. We should also decrease the damage the wall can do, to minimize the effect it has on other teammates. This is just an idea, but maybe phoenix can pull his wall down, creating a line of smaller phoenix mollies where the wall used to be, making more unpredictable and creative plays for Phoenix.

Phoenix's Blind - Phoenix's blind is very predictable and bad, as other blinds such as Skye's and Breach's can come out of all sorts of angles while also being quicker to flash enemies. This gives enemies a lot of time to just turn away from the blind. To prevent this, the blind could move faster and activate faster to make enemies peeking at the blind forced to fall back, allowing Phoenix and his team to push forward quickly. The blind could also be invisible from longer distances, making it more unpredictable and forcing enemies holding areas such as Bind Heaven on A site with long-range guns such as an operator forced to fall back. The last part might be a bit too much, but they should at least add the first part.

Phoenix's Ultimate - Phoenix's ultimate is very good. It allows him to get intel and get some picks along the way. It's like attaching a gun to Sova's drone. Though, this leaves the place where phoenix ults very vulnerable. To fix this problem without removing the vulnerability, Phoenix's ult should be invisible unless you come into a close radius with it, sort of like Yoru's teleport. Making it harder to camp Phoenix's ult, but still having that vulnerability to it. Not only that, but every time phoenix uses his ult and comes back, his shield is removed for some reason. I think that if the user had a shield and ulted, it would give that shield back when phoenix comes back. If you had light shield before ulting, you would have light shield. If you had heavy shield before ulting, you would heavy shield. If you had a shield that was slightly damaged to something like 10 shield, then you would get 10 shield when you come back.

Conclusion:
That's all I have to say. This is my first time doing this, so I don't really know if it's "overpowered" or "the right way to play phoenix". Feel free to criticize, I would actually enjoy getting criticism. Thanks for reading.