If you had gyno removed (your mammary glands taken out), then there is no biological way you can get gyno again. If you just had liposuction or fat removed, then yes you can get gyno. 500mg of 4ad can definitely cause gyno if you are prone to it. If one was running nolva with it, that should eliminate it. What type of surgery did you have?
T-gel can definitely irritate your nips. I get a rash every time I apply it anywhere on my chest, but everywhere else is fine. If you had gyno taken out, I'd guess it's a combo of t-gel irritation & paranoia. There should be no need to run nolva on-cycle if that's the case.
Many recommend taking anti-e's at night when E levels are highest. I find that nolva causes insomnia for me, so I take it in the evening.