Well, just remember that one can't always be everything.
I haven't tried a frumentarii build before so I couldn't say how it should be.
But I do know that there was a thread a while back about a frumentarii build, try searching for it.
True you cant be everrything, but my current character s lvl 29 house faction. And I think by 35 he will max all but 3 skills.
All I really need is a guy who can be sneaky, so lockpick, sneak and speech. But at the same time be strong enough to be a elgion, survivial, melee and guns. I may drop unarmed, though that would look weird if I ever decided to RP him being promoted tpo praetorian. Oh and repair is just for survival, I doubt many people will want to trade when I commit myself to the legion...
Will the gun runners hate me ? If I cant do much I may have a use for that gold after all, make sure to get plenty of caps before being isolated.
Which characters will tolerate a legion member ? I know cass hates evil, but I will have to fight ncr so its inevitable that she will hate me, arcade will hate me, boone will, veronica probablly will when I wipe out the BoS.
God I forgot how much it svcks to be legion.