[bottomset]

uh Q5o isn't a stealing hand unless the blinds are very rockish

my base button steal hands are:

any ace, suited K's, K7o+, occassionally suited Q's, any pair
occasionally a hand like JTs, T9s

cutoff:

suited A, A8o+, K9s+(occasionally K8s, k7s), KTo+, pairs

the biggest factor in HU blindsteals is High Card Strength .. and showdown value UI

defending is a much more complicated topic and very player dependent .. though typical hands in the bb are suited connectors, aces, suited Ks, Qs, good offsuit connectors