Help Climbing (Currently P5) (Many Questions/Struggles)

Having a problem. I some how managed to start having positive kda's in more of my games, but now, some games feel like I am the only one who can really save the game. If I make one mistake its over because my team will never survive without me. Unsure if I am getting unlucky, but games have turned from either stomp or every lane loses, to stomp and every lane lose but me but unless im 15/3 or some insane score the game is essentially over. I am platinum so I'm not gunna say "well if my teams didnt feed"

I have tried to think of many solutions but they all seem to have flaws

If I have to play perfectly to win these games, then it would seem that smurfs would have a considerably hard time climbing since the games would be 50/50 (Which is about how often these games seem to occur), but this is not the case. There are smurfs who play solo lanes and easily can get above 70% and even approaching 100% winrates in any tier below diamond.

If its my macro, then how could I alone out rotate or just out macro the entire enemy team without pressure from my teammates?

If its lack of pressure during laning phase, then why do some coaches/high elo players say to try to only focus on your gameplay? I have even heard some say to just focus on getting cs and not risk a fail roam attempt

It just seems harder to snowball games for everyone, which I think I was doing very consistently at my peak at p2 100lp (op.gg said I had mmr of d4)

I have been having better games kda wise lately too but the wr is hovering slightly above 50%, but not enough to really climb in a reasonably amount of time

If there's flaws in my reasoning throughout this post (and there most likely is) please point it out.

Here's my op.gg http://na.op.gg/summoner/userName=Galaxy%20Fighter And don't just make comments saying "well you have bad cs" or "high death counts" Give indepth reasons on how to fix this.

For example I know my cs only tends to plummet after laning phase, meaning its not that i cant last hit, I just don't know how to farm well after laning phase.

My death count is high I think due to risky plays but I don't really know when something is risky or not The explanation "Just dont do it if theres a high chance of failure" or something along those lines doesnt really cut it. Some plays just look so good but then oh fk nami heal just left both of them at 1 hp. I always rage and say they got lucky but its not luck if its happening all the time.

I am assuming as vlad I shouldnt be initiating fights, but what if no one will or can? What if we are letting them siege tower after tower because no one stops them, should I engage to stop them if I think we can win? What if the team comp has no initiation should I be in place for one?

Are 2 for 1 trades worth if I am insanely ahead? (I seem to do it quite often)

These are just a few questions/problems I have. Anyone who thinks they can answer is welcome.

Thank you if you read the entire post (: