This trunk is still thin and flexible enough to slap some copper wire on and bend into an interesting shape and then let it grow for a few years, as one always does to produce a tapering trunk. The alternative, of course, is to develop the classic zig-zag trunk line that uses a branch at the lowest whirl to become the next straight trunk section. But you'll want to grow it until the bottom section of the trunk is about as thick as you want to have ultimately (developing taper relies on the fact that it won't thicken much until the stem above is about the same thickness). At some point you will have to repot the tree with to affect a slanted (bottom) trunk to make a zig-zag trunk style.
However, you've made it clear that this puppy needs to be repotted. First, I recommend that you put it into a pond basket (which in my experience you can get in an instant at Home Depot, if not elsewhere) filled with your chosen bonsai substrate. This will allow you to have fun developing it over several years' time without the set-back that always comes with repotting. As for getting it out of the present pot, you can always just cut it off - insert scissor point into the drain hole and cut upwards. On the other hand you can lay the pot sideways atop a block (like I see in your photo) and forcibly lean on it while you roll it back and forth - the pot should easily pot off then. Smacking the pot sides with a heavy rubber mallet will also work (and, for future reference works on ceramic pots without destroying them).
Candle selection, meaning reducing the number of candles to two is something I think best left until close to or in winter with JBP, but it probably isn't a big deal one way or the other. Each branch is essentially independent of the other, so you can experiment to quickly learn how all this stuff works by trying different things at different times on different branches. For example, you could cut all the buds off a branch tip now and see what happens. If you do this early in the spring, you'll get new candles (minus any necks from pollen cones). The needles on these 'summer candles' will grow until the end of the season - candle too early and needle lengths may not be any shorter. Candle too late and the tree might just set new buds that won't push until 'next year'. For me, decandling at the end of May gives a nice needle length. Guys in the Bay Area or the southern states my need to wait until July to get the same result. So, you might try removing all buds on a branch tip and just reducing the buds to two on another now, for example. More along this line is that one can prune off a large chunk of the foliage of one branch. It seems that if one does this is spring (prior to the summer solstice), the bud and the base of a needle pair will get released to produce a new shoot. If one does this later in the season, a similar outcome will result, but not until the next spring (next year - should I say 'I think"?).
A fundamental fact is that we humans cannot make a tree grow, We can only selectively weaken branches to achieve our ends. Needles are leaves and leaves produce the food that is the raw material and energy for making more tree. The more foliage there is on a branch, the more rapidly it will thicken over seasons. However, leaves are not particularly productive if they are shaded from sunlight. Needle plucking is just a technique to reduce the vitality of the branch and/or to improve the sun exposure of foliage on a branch below. Plucking needles, though, effectively kills the bud at their base, which means less opportunity for budding back. Budding on bare wood is relatively unlikely, but more likely at a branch node. In a development state, one wants all the foliage they can get at the end of the sacrifice branch (to make it thicken rapidly), but doesn't want to shade the foliage below (since it will be the foliage of the bonsai). But again, this is something you can learn about by experimenting on individual branches. About the only thing that takes the whole tree is that back budding is best and often seemingly spontaneous with a vigorously growing tree (and these have a lot of foliage).
Anyway, there's a ton of fun stuff to do while (eventually) developing a bonsai trunk from what you've got, The cool thing about bonsai is that you can always change (the style of) what you've got, if you're not loving it. It is just time (as I've been told many, many times) and a new design/styling challenge. Regardless, you will never know until you try. The important thing is to have fun with it.
