I always saw it as when they were back living again they were sort of zombified. Like they could die again but it probably wasn't gonna be a health issue that would kill them. As for becoming stronger, thats a stretch. Madison was next in line to be supreme as it seemed for a while so I think her powers would have grown whether she died or not. Not to mention Cordelia is the strongest witch and she was never dead/brought back to life.
I agree, I think being revived makes you stronger. Misty started off as a really timid looking church goer and when she arose she was off slaughtering alligators hunters and embracing her true self. Myrtle seemed to become a little more wicked (i.e. killing the council). And like you said, Madison's heart murmur was gone. I'm sure Zoe gained something from her resurrection, we just didn't have much time to see what it was. I'm happy with where they left her character though. She grew a lot throughout the season.
I think so about that too. Maybe they can heal and take away the bad stuffs from you? (i.e. sickness) and add more power. Just a thought.
I thought this was a given, being that Myrtle said she learned a few tricks from the other side. I forgot about Madison heart murmur, so maybe if she didn't die and get resurrected she wouldn't have had all those powers. She gained a total of 6 of the seven wonders and resurgence, after she was resurrected. So I agree.
Appearantly being burned at the stake and then coming back has some healing effect, which they don't explain.
Regarding Madison, she was going to manifest those powers anyway.
No, she already had some Wonders before dying;
Telekinesis, her signature power
Pyrokinesis, which she displayed on Joan's curtains when she was pissed off and Fiona's cigarette when asked to
Concilium, which she used on the man on the street when Fiona asked her to do it
Arguably, Descendum isn't really a power that one can gain; it seems any witch can "go down" if she says the word, the trick is coming back and magical ability doesn't seem to be the criteria here, I think it's about willpower. Descendum, as a Wonder, is a test of the witch's mental toughness.
She definitely gained resurgence (the man in the coffin, the fly). Given that she has resurgence, it's hard to confirm whether or not she has Vitalum Vitalis, she didn't breathe into the man or the fly, which seems to be how VV works.
The most important part imo is that dying cured her of her heart murmur, which is the number one reason why she was back in the competition for Supremacy, otherwise she was disqualified by default.