  We studied 93 asteroid pairs. We estimated times elapsed since separation of
pair members that are between 7*10^3 and a few 10^6 yr. We derived the rotation
periods for all the primaries and a sample of secondaries. We derived the
absolute magnitude differences of the asteroid pairs that provide their mass
ratios. We refined their WISE geometric albedos and estimated their taxonomic
classifications. For 17 pairs, we determined their pole positions. In 2 pairs
where we obtained the spin poles for both components, we saw the same sense of
rotation for both components and constrained the angles between their original
spin vectors at the time of their separation. We found that the primaries of 13
pairs are actually binary or triple systems, i.e., they have one or two bound
secondaries (satellites). As by-product, we found 3 new young asteroid clusters
(each of them consisting of three known asteroids on highly similar orbits). We
compared the obtained asteroid pair data with theoretical predictions and
discussed their implications. We found that 86 of the 93 studied pairs follow
the trend of primary rotation period vs mass ratio that was found by Pravec et
al. (2010). Of the 7 outliers, 3 appear insignificant (may be due to our
uncertain or incomplete knowledge), but 4 are high mass ratio pairs that were
unpredicted by the theory of asteroid pair formation by rotational fission. We
discuss a (remotely) possible way that they could be created by rotational
fission of flattened parent bodies followed by re-shaping of the formed
components. The 13 pairs with binary primaries are particularly interesting
systems that place important constraints on formation and evolution of asteroid
pairs. We present two hypotheses for their formation: The pairs having both
bound and unbound secondaries could be `failed asteroid clusters', or they
could be formed by a cascade primary spin fission process.
