Oh gosh got old amber from smashing rock. Haven't even reach 2nd gym yet. 

There is. I found one just after the first place with the bug gym. But killed it with a critical strike

Wow female charmander for ralts?
I have 2 ralts here I think. Need to check after work.

Not all , only for physical sweepers or physical fighters.

Not really. Adamant nature is not for all but works best to any Pokemons that have a high ATK stats for example Pancham. As for Charizard, the preferred nature is Timid as it increases speed but decreases ATK or Modest or other natures that complements Charizard stats distribution. Charizard S. ATK is higher than ATK, there's variety of S.ATK moves to use.. so yeah, go for Nature that doesn't hinder its S. ATK or speed

Personally I would go for hit hard but most of people online who plays Pokemon competitively will choose to Speed over S.Attack as it seems wise to have your Pokemon faster than the opponent

example of gardevoir

most preferred nature is modest -ATK + SPA
with the beneficiary nature you can get 280 - 383 SPA

if you not get the nature + SPA
you might get 255 - 349 SPA

if you get adamant for gardevoir would + ATK - SPA
which is not benefit to gardevoir at all
you might end up with 229 - 314 SPA

by move pool and it max base stats
BASE SPA: 125
BASE Attack:  65

so go for modest
BTW VERY IMPORTANT:
CASUAL PLAYER DONT THINK BOUT THIS

For ralts, Adamant is not really good. But like I said earlier, it will function ingame but it will pack less punch than it should. Another but, that is if you're evolving ralts into Gardevoir. If your ralts is a male, you can evolve it into Gallade which is fighting/psychic pokemon. The adamant nature works well with Gallade since it has high attack stats.

Modest works for Charizard. Greninja.. I have no idea. I read that its ATK and S. ATK stats are equally distributed so it could go either way.

Well you just have to look at the type of the move. Check the moves description and you can see whether the move is a S. ATK move or a pshycial ATK move.

You can guess the Pokemon stats if you look at how it the stats gains or when it leveled high enough.. But I usually check other websites to look at their stats distribution.

Again. Ingame = everything works. Just don't mind the natures so much or you might not enjoy the experience. Just go with whatever you like. Think like this, if Pokemon world is real, you're a trainer and you've been given a starter by professor sycamore, will you just throw your Pokemon away when you noticed its not as strong as the others? Lol 

lol I would breed them and make a stall outside the first city. Starters for sale, victory road Pokemons for sale, dragons eggs. lol.. I know a lot of people would come buy.. But.. wonder if the starter trainers have money..

i finish game usually help people breed the best pokemon 

i find liao i just catch ditto & keep breed and donate only, me no like battle 

i hv extra modest ralt but not wit sync