You know, if you've only played for 3 hours, it might (just MIGHT) be worth it to reroll till you get a haul on your first half-off pull.
Your call though. Those 4*s are decent to start of with, and your existing 2 5*s are pretty good.
Depends how hardcore you want to go at this game I guess.
In terms of XP eggs, I'd use them on characters you know are gonna be using a lot in your party (e.g. Cloud, Vivi, a good healer, a good support guy, etc), but I'd do it only after Orb Dungeon ends since that's very, very easy XP.
In terms of equipment, keep in mind that the "record synergy" mechanic makes stuff way more useful in their respective realms if you upgrade them even to 5/5 2* or 1* combined. A fully combined and upgraded 2*++ at 15/15 used in its corresponding realm, for example is usually as good stat-wise as a non-Synergy 5* in a specific realm. 1++s are nothing to sneeze at either when you've just started.