yeah there really should be a rolling sort of thing when it comes to 5* relics... Sorrow, you know the one in Heavenstrike Rivals... dunno why they don't just implement pretty much the exact same thing in FFRK.
i got Rinoa's weapon from the starter banner, too. a high MAG thrown weapon is one of the few things i was lacking (been playing since like week 2)... i still haven't used it for the purpose i intended it for, tho -- in the hands of a ninja character, since ninja skills are based on MAG for whatever reason, but ninja usable gear almost never has MAG on it.
anyway, RE: disappointment when pulling items.... the best approach is really just to expect nothing. but you newer guys, keep in mind that even 3* items actually get pretty damn good once you combine them and use them for realm synergy. a 3++ with realm synergy is typically equivalent or slightly better than a 5* without synergy. so.... even if you pull nothing but 3* items, you'll eventually be doing okay.