the place you mentioned next to the dollar theater, is that champagnes? if so, theres also one at northpark plaza on irvine blvd.
not irvine, but pacific whey in newport beach, crystal court, and crystal cove is fantastic. my favorite pastries around.
panera (yeah yeah i know its a big chain place) is nice place to lounge for a while. i often read, study, or even work there since they offer wifi.