do it Mark, the kootenays are great (so are many places in this province, though)…I might skip living in Trail (the smelter still pumps out alot of nasty shit and it's one of the only towns in the province requiring you to have your children tested for lead levels regularely).
Castlegar is nice, very blue collar but experiencing quite a housing boom in the past 8mos and the demographic is definitely changing.
Rossland is great, a friend moved from Nelson 6 months ago and got into a little fixer-upper for less than $120k, seems pretty happy with the community and brewery there. From the time I've spent in Rossland though, there's not ot very many single women (byo-girlfriend) but Trail seems to have plenty of tail as well as job prospects, better pay and it's really just down the street from Rossland. There are also many small communities (really just a dot on the map) between the communities here, so if you're looking for a more rural place outside of a town, check some of those out.
I notice you didn't mention Nelson for a place to live, good choice. High cost of housing, insane property taxes and next to no services. Great place to come and visit or see some live music but it had it's heyday in the mid-late 2000's and isn't the place it once was.
Not sure on the demand for contractors in the areas you're looking for but in the Nelson area things are booming and there's alot of work in the trades right now, you'd probably have no shortage of work taking on small projects that the big contractors turn away right now. The commute from any of the communities you mentioned is a breeze compared to the city (winter driving can be a bit sketchy at times) but all that to say you could likely base yourself out of Rossland and get alot of work within a 1hr radius, Christina lake to Nelson and beyond.
PM me if you want more info, I've been in the Kootenays for…12 years now and I'd be happy to point out some cool areas to check out before moving up here. I like rural so I bought property in the Slocan Valley but if I was looking for a more urban environment I'd pick Rossland in a heart beat.