So after taking off the clapboards and trim, the story was revealed - some body's been over for dinner.... and they brought the whole family.
... no wonder this corner felt "bouncy"
So like every other project (why should this one be any different) - it just got unexpectedly bigger. After studying it a bit, all was not so bad, those pesky termites didn't stay for dessert. Looking at the construction, what was ate up was the first four feet of the outer floor joist, actually a doubled up one. There are 4 support beams which run from the stone foundation of the main house and tie to the brick footers. Then the floor framing rests on top of these beams. Nothing major in the floor had been touched and best of all they never made their way up the corner studs. So ended up just a matter of replacing the damage. Plus I didn't even need to support the corner of the house while making the repair.
I was able to stagger the joint from old to new since it was two 2x10's sistered together for this end joist/ledger making for a strong transition. There will be a 2x8 on the outside for a deck and another 2x10 on the inside to support the new floor sandwiching this all together - making this corner stronger now than when it was built.
Note: the cinderblock is just filler between the original brick footers that was added sometime in the past to block drafts.
Much better now.