Value = NOI/Cap Rate
No clue on the accuracy of your cap rates, but assuming they are correct:
Building 1 = $319K
Building 2 = $322K
Building For Sale 1 = $500K
Building For Sale 2 = $656K
So seems you are pretty close with your values except for Building 1.
The 2% Rule is simply GSI/Market Vale (or purchase price, or ARV, or whatever you want to use). You don't have your GSI, but assuming you applied vacancy rate of 6%, we can figure it out from the given GOI. Gross Operating Income (GOI) is Gross Scheduled Income (GSI) - Vacancy Allowance. GSI = Total Rent value of all units in the property.
Building 1
GSI = $54,600/12
$4,550/$319,000 = .0142 or 1.4%. You aren't too far off and keep in mind it is often extremely difficult to meet the 2% rule in many markets. While the 2% rule is a great metric to use, it shouldn't deter you, especially if the property will cash-flow well.
Meanwhile, the 50% Rule is simply that your expenses will be about 50% of gross fair market rent for the area. All of your properties seem to meet this metric and that is only using the GOI you give as opposed to the GSI.
Building 1
GOI = $52K
Expenses = $19K
50% Rule = $19K/$52K = .365 or 37%. So you easily meet the 50% rule.
But based on the numbers you supplied, all of your properties appear to be meeting the 50% Rule.