Oh, for sure, Dinah's very, very hetero. Babs comes across as gayer than labrys-shaped monster trucks all by herself, but the only thing at all slashy about Dinah is her relationship with Babs; Dinah/Diana is a fairly common pairing in DCU femslash and even that is really hard to sell me on, just because Dinah's so incredibly straight. But people are weird; the gayest guy I know fell for a woman my sophomore year of college. I read Babs as Dinah's exception, just as Dick is Barbara's.
I do not blame you for having trouble with the Land covers. I'm not actually particularly bothered by Benes' early work on the title - he gets worse as he goes along, but even at the end he's nowhere near as epically crappy as his JLA work, and still head and shoulders above Joe Bennett, who replaced him - but I've been seriously contemplating putting some opaque laminate on my Birds trades since the day I bought them. Just... no, DC. Bad comics company. No biscuit. However, at least there are trades for those hideous covers to be *on.* The vast uncollected swaths of BoP make me an even sadder panda than the appearance of those that are.