Planning subfloor work

Hi all, I'm planning on ripping up my tiles and flooring to do some sub floor work and putting down new flooring and I'm after some advice. I'm in Wantirna (VIC), brick veneer, tile roof, concrete stumps, hardwood frame, built in the late 70's.

I have some old termite damage in a bearer (that's now squashed) that I'm going to replace. I also have an area that the joists (2x4) are spanning over 2.1m. Which is resulting in bounce in the kitchen, so I'm planning a row of stumps and a new bearer. I have bugger all room under there so I'm planning doing this with the floor up.

<O</ONow, I have two doorways that have gone out of square and some plaster cracking diagonally from the top of the door jam. I've checked underneath and I cannot see any evidence of sinking stumps, no daylight between the timbers. I'm not all the fussed if they are out of square, but if I have issues, I should really get it fixed while the floor is up.

<O</OShould I get a restumper out to check the stumps before I start or is this just the clay moving from the drought? Any advice would be appreciated.
<O</O
After I’m done I’m planning on putting down yellow tongue, then direct sticking bamboo overlay flooring, about 35sq/m.