1. Renekton does very well
2. Yes ANY ELO. If you are good with any champion. It can WORK.
3. The FOTMs. Graves, Lee, Rammus, Skarner, Vayne, Tryndamere, Irelia
4. Top is not as a great impact in the game compared to mid lane or jungle

Speaking of mid, how do you know when you should roam and when you should stay in lane?

When your lane is pushing aka you pushing your lane.

lol duh. Also only do so if other lanes are being pushed,.

well yeah, but what champions shouldn't you roam against, if you have them in lane, should you roam if you're behind on cs? ahead on cs?

You can roam anytime, but try not to roam against strong pushers.

You answered your own question.

You shouldn't roam when you are behind in cs.

to counter 4 you pick nasus. He will have an enormous impact and will win games even if 7/14 or something like that. Top can have a great impact if you pick a high scaling champ like nasus or another ranged carry like vayne.

morde solo top wrecks their bot lane later on when i go to gank em, i some times just have my jungler hold top then i gank unexpectedly, usually getting their ad carry ghost, and it will some times be a double kill, ive even goten triples because jungler came and i had a ghost or he was already there, then we usually kill the turret, i think some top solos can make a big impact, but chars like renecton/garen will just fall off late game and most likely wont even be that important

best way to stop singed/skarner at games? so annoying

Why did you get carried to that elo ?