2. That's relative to your season and how the tree is responding, to expose the bare roots and cut the taproot, for most species, you do it late winter / early spring (if the plant is ok).
3. After the tree has adapted and begin thriving, you can already start fertilizing it (according to season), but use organic fertilizer or osmocote grains (slow releasing NPK), don't use simple granulate NPK, it is good, but it's extremelly dangerous, apply it the wrong way, or the wrong quantity once, and your tree will die.
4. You got it wrong, I also thought this was the way when I first started, I kept pruning back and waiting for trunks to thicken, and didn't happen... The only way to get a fat trunk is letting it grow, ramificate a bit so it can grow as many leaves/branches as it can, with that leaves high demanding your tree, the trunk will have to thicken in order to flow all that extra sap.
5. I don't know how long almond trees still flexible, but for the trunk movement, you should see the edge of it's flexibility, only on the trunk having in mind that at this point mostly just the base will mather, as maybe a few years from now you may want to add a more conical shape to the trunk (I don't know if that's your plan), having to prune it down an choose another leader to thick again, but little less, and so on.
Some people even add movement chopping the trunk and changing leader, it will let your tree with some large scars to heal over the years, so if you go for that someday, remember that different trees heals differently...
If a trunk get's too hard to add movement, you can always chop it back, and start all over... hahahah. For slightly bends tho, still there are some other techniques...
Trees are really different on this matter, a ficus is really flexible for example, but a Calliandras are already stiff when it reaches the thick of a pencil.
However when wiring young sapling trunks, you may always let it a bit loose, so it won't bite (at least too much) the trunk as it thicken.
A little bit is no problem, when the tree is young it's easier for it to recover from wire marks.