Growth for boas varies a LOT. My boy was 2.5ft at a year old, which is pretty common for Colombians. But, for a year old you're normally looking at 2.5-4ft, although I've heard of 5-6ft even. As to whether or not they were power fed I could not tell you. I've always been told the most growth is during the first year. That was not the case with mine. He grew less than a foot his first year, and by his second year he grew just over 3.5ft and at 2.5 years old he's about an inch shy of 6ft.

My experience has been that they're much much easier on the nerves because most of the time they do not refuse meals (mine never has except for 1-2 months where I was feeding rather large meals and he went back to normal when I stepped back down in size), but their temp requirements are basically the same as ball pythons. 90F hot spot, 85F hot end, and 75-80F cool end. They do require higher humidity at 65-70%, but I haven't had any problems with that (until now, but he's only 5-6ft away from the heat source now so that's probably it). There is absolutely no need to drop temps at night unless you're breeding. You can if you want, but it's not needed. I have never provided night drops for mine and I've had no issues. I find if he wants a nighttime temperature, he just hangs out on his cool end. Because of that, I feel there's no need to give a drop if you have a cool enough cool end.

As far as male vs. female I have no clue, I only have a male. Size is subjective as well, and depends on the subspecies. Colombian males can average 5-6ft and females 7-8ft, but even males can get as big as 8ft.

I kept my boa in a tub the first 1.5 years I had him, so that will be fine as long as you make sure to upgrade in size as it needs it.