Yeah, just a polite amount of tension is the way to go. Enough to release the brake and no more
Did you deglaze those new pads before putting them on? If not, whip em off and give the faces a rub on some sandpaper until they loose all their shine. Clean the rim with glass cleaner or vinegar and water. (or brake cleaner if you're a mechanic type).
While you're down there (snigger) doublecheck that both brake arms have similar tension and are both equally free running on the posts. Can't be having any of that lop sided brake nonsense
As long as you've run the straddle all the way around the seatpost and connected it in front it, there's no worries there, the angles are a bit kooky on all brakes I reckon, but not enough to upset the brake power.
In my experience very nearly all pads work well on chrome rims. The only thing I've come across is some pads can be bloody noisy..... Clarks pads out of Halfords work a treat for £6 if you fancy a change.
