Sounds like you wound up with good alignment specs and most importantly it drives well. Agree you could push the negative camber a little (?-.75) w/o tire wear problems but you are close and it drives well so no hurry.

It would help to find a safe place to push the car to its limits to see how it does and guide future improvements.

As far as rear springs, there are a number of posts on this. From memory, stock E springs are ~120 lb/in and XHD are ~140 lb/in. I run XHD with one full leaf added which comes out to ~170 lb/in. Combined with 1" front bars it seems pretty balanced with my combo. Bigger front bars and better shocks will be my next upgrade.

Lots of views on T bar size. A range of 1.00" to 1.12" seems to be the sweet spot and a beefed front sway bar is an important part of the setup. Going over 1" needs higher end shocks for both comfort and performance. The rear sway bar maybe/maybe not.

I don't remember if you have installed frame connectors. These help in general and especially as spring rates are increased. If the chassis is flexing the stiffer springs don't help as much and flex is really hard on the chassis and body.

As far as brakes, it depends a lot on how you will use the car. For street driving a well set up factory disc/drum arrangement should be fine. If you push it hard on a track, you will find the brake limits pretty fast. There is nothing quite like the smell of burning brake material.