[Baalz]

Well, the thing about transformation is it completely removes upkeep cost. The upkeep cost of a unit is 1/15th it's cost, so if you transform 15 mages your upkeep savings will give you gold for a "free" replacement every turn. I don't know what the failure rate is, but if it's 10% (and you ignore the gem cost of transformation) then it pays for itself in less than two turns. That is to say if you have to pay for a replacement mage 10% of the time you can do it with the upkeep savings after a turn and a half. This also discounts the fact that the mages after the transformation are significantly more powerful if you plan to use them on land. The failure rate is further dropped if you just stash those upkeep free feebleminded dudes somewhere until you've got a bunch of fairy queens sitting around to heal them.

As to the A5, that's a bit of a judgement call but I was thinking about wind ride when I did it. Also, until you get all the way up to conj-8 your pretender is your only air support and it's useful to be able to cast fog warriors and not pass out (A5 with 5 gems) so you can then cast returning the next turn to keep your pretender relatively risk free. You could put the points elsewhere if you want, but it seemed a decent investment.