1. Expected life is limited by HDD life (spin up/down cycles, probably), but these are off-the-shelf parts and easily replaceable. The buttons are unlikely to wear out. The display may get burn in after a long while if you stick to one info display.

2. Load up some tunes and check it out. Run it for 24 hours at least. They're all given a thrashing in the factory test rig, so there should be no issues - and we're not going anywhere! Even many years down the line I would expect that at least one of us (eg, me or Patrick) would still be selling spares and doing repairs as a hobby :)

3. The mk1 has more issues with the design than the mk2, the display is the most likely thing to have problems (due to voltage spikes). The mk2 PSUs are better protected. Again, not hard to fix and mk2 display boards will fit onto a mk1 if you remove the rotary control :)

You can currently downgrade software if you want, I suspect this capability won't be removed.

Hugo