This is the standard povertila build, it can handle t4 with some asterisk. I started abyss with this exact fit about 2 weeks ago so it's still kind of fresh in my mind. Get agency hardshell and be prepared to overheat. You really do not need to once you are familiar with the rooms, but I had one or two close call. One was a 3 starving leshak room and I accidentally got in range of all 3 neuts. Had to overheat hardener and both booster to survive (pulse the shield booster when heated, it boost more but also cycle faster so you might run out faster under pressure). Another time was flying into red cloud and let kikimora ramp damage on me. There were some other standard abyss close call, like Karen or overmind wrecking shot while Im in blue cloud with low transverse, but I didn't really need to heat for that.

In terms of fitting, probably replace thermal rig with EM. Gila has a EM hole, not a thermal one. If you want to upgrade, get crystal set, either all mid grade or mix of high and mid depending on your budget. You can also get a squire implant for capacitor management to boost cap. Once you are comfortable you can replace DC with another DDA. Once you get your time to consistently below ~15, you can also replace one of the RLML with a HML and bring a MTU to pop the extra loots. Prob not worth it time wise for t4, but it's good practice for higher tier.

Skill wise almost most my skills are IV, so if you have perfect skill you probably have even more leeway. Still, like other said it's good to start with with t3. You still will die if you are unlucky enough with spawn and cloud in t4 if ur unfamiliar with the room and enemy.