More Questions Concerning Silver Promos

Okay, so let's start here:

1. Lost promos into silver for the third (?) time, feeling bummed out but knowing that I'll get back there and probably pass them next time.
2. and are the two champions I feel comfortable with in Ranked at the moment; the other champions are those I am either not as comfortable and only familiar with via guides and occasional play, or have been turned off of due to repeated losses with them (, ), or they kept getting banned ().
3. I've come to the conclusion (based on replies to earlier posts) that I am not going to be good at all with early-game, aggressive champions who need kills/assists to snowball and do well (///assassins), high-mechanics champs (//), or ADCs in general (too much time trying to position or farm, not enough harass/sustained DPS on enemy champs).
4. In a game, I want to be able to build power by farming, not by going for kills (too much chance of losing the trade because sustained dmg/hyper-regen/crits/outplays, or getting ganked when the wards I place have expired/been smashed/are on CD).
5. I want to win by going straight for the buildings when I can safely do so, but I also want to help my team to keep them from falling behind, or to keep the enemy from trading objectives. Worried that if I split push, the enemy team will group, destroy my allied team and push somewhere else faster than I can alone. Never mind the odds of getting caught out (again, wards), but I don't want to be the one everyone flames for not grouping (barring when I mute everyone to keep them from bringing me down with their toxic rage).
6. Looking for champs with low difficulty, who can impact the game without needing to go ham or being too co-dependent on allied performance. Preferably someone who can take objectives without getting blown up instantly, or absolutely needing to dominate their lane early on. Someone who can be played in multiple positions with little variance to their build or actions (save /supp trinkets/ + upgrades). Must also be satisfying. (This is a bit idealized of a description, so anyone close to said description in at least a couple of areas will do).
7. So far, loosely considering / / / // as possibilities. I'd want to use somehow, but his ability orders and combos for efficiency are a bit confusing to me, plus all of the times I've been as him the team fell behind or I was against a top laner I couldn't burst down.
8. I tend to post a lot on the forums after a losing streak or a couple of demotivational losses, asking for advice or assistance that I can use on my own time (no classes, no Skyping streams, no patience for having tons of optimal game variables crammed into my face such as "how much of this do I need to have by that time in order to win" or "if you face X or Y as Z in this area, you might as well uninstall the game and hang a sign on your neck stating that you have absolutely no potential", nothing Ramsey-like here).