Do you guys think that if you a play a champion you love enough and master that champ he could carry you to challenger or is there a point where you have to give up on that champ and play the easiest/snowbally/fotm or whatever you wanna call it to climb?
I think that having mastery over a champion will give you a strong advantage over people playing Fotm champs because they are Fotm. Knowing the capabilities and limits of a champion gives the ability to make better plays.
That being said, the Fotm champions are usually Fotm for a reason. If two people are of equal skill level with their champions, I would think that the Fotm champion does have the advantage.
I think it also needs to be said that playing a champion outside of the meta makes it more difficult for your team to know what to expect and/or makes it harder to synergize with them.
So in an ideal world where every champion was balanced perfectly and every person knew how to play the game perfectly, I think yes, you could play any champion to challenger.
But champion imbalances, differences in player skill, and even team composition its self may make things like that more difficult.
maybe not challenger, but if I mastered the ins and outs of something I loved, I could go pretty far (I mean, last year there were challenger Urgot mains, so if they can, I don't see why anybody else couldn't).
Maybe to Platinum/Diamond. Challenger is a stretch. I was getting pretty good at Tank-gas 
before the Cinderhulk addition (was playing him Top and Support). So keep that in mind when you have a champ that you love. They will become Fotm at some point (unless you are 
) and you will have an early advantage in a meta that includes your champion.
The same thing kinda happened with Urgot and his buffs. People who main these champs understand the buffs early and use them to the full potential early. However, playing non-meta champs usually means that people didn't know how to play against you, which gives you an advantage. After people see more and more of it, they learn to play against it.
I think if you really enjoy a champion, play that champion as much as you want. Get really good at playing that champion and break him out in ranked if you feel comfortable with it. But don't rely solely on that champion. Especially since you won't be getting the role you always want. For safety, find 3 champs in every role you feel really comfortable with. Some can crossover, and that's fine, but there is danger in only having a few champions in your pool.
I would also encourage using some of the champs who seem to be good in any meta and are kind of "jack of all trades".
ADC
Mid
Support
Jungle (I don't like Lee Sin as he is technically challenging and really doesn't translate into teamfights very well)
Top lane is kinda tricky but 
fits into many teamcomps and he is very easy to play
The other big advantage of playing these champs is that they are played a lot and you can better understand their strengths and weaknesses by playing them.
