I have a gob of this stuff too, I use it for some HF stuff. Note the A/U means it has a stranded center conductor, so its a little different to solder typical with connectors. As far as your questions:
Look at the data sheet. You will see as freq goes up, so does loss. At 25 feet...eh its prob okay but that's your call as far as how much loss you can live with. I only use mine for HF.
1. Is this OK to use for 2 meter? Your call, Lossy at this freq
2. Is this OK to use for 440? Your call WAY Lossy at this freq
3. Is this OK to use for HF? No worries
4. Is it a OK to use a PL-259/SO-239 with 440? I have heard otherwise, but notice this is what many radios have on them. Its not really a problem IMO, A BNC or N is less but...
5. How would I put a PL-259 or BNC connector on it being that it is slightly smaller than RG 58? Your a HAM, adapt it, I bought an adaptor for standard connectors. No comment on the BNC's, I HATE putting them on
If it were me, I would stick with at least 8X for short runs UHF/VHF, longer runs LMR 240 or 400.
73 Dave KD8GEH