I did a couple of quests to NCR and i still have a neutral reputation with them.
Is it normal at lvl 10???

Here are the questes that i could remember i did (probaly i made olthers too) :

All mojave outpost quests
I put the NCR guy as a sheriff at primm
HELIOS quest and put the power at the cities NCR suggested
Quest at NOVAC that a ranger ask me to go to some kind of outpost to see why he lost comunicattion with them

have you killed any of them?

that should be enough really, unless you killed some.

its usally takes a while for it to go up a peg at 1st then its starts going pretty fast i think it took about 7-8 quest before i got up to accepted
and if you are wear a faction armour in your dealing with them that can also effect it if there enmenys are netral with them




i also find shooting is a bad way to make friend to (but they started it)

No i didnt