ARms and Equipment Guide is fine, except for the part about buying feats to put onto items. That is banned, though it shouldn't matter much since custom items are banned.
Yes, the Elephant rules should fix your problems.
That sounds fine.
You get to roll two sets of seven rolls. So although you have rolled really well, you get a chance to improve it a little, as you only rolled twos ets of six rolls.
Just spend gold on your items to make things easier, and in case it matters treat it as if you spent xp.
Intelligence score uses are retroactive, so if it improves just treat it as if you always had it at that level. Makes things easier for everyone.