1) If ledger goes out of business or offline, you can always recover your funds on a compatible wallet. What is a compatible wallet? See this: https://support.ledger.com/hc/en-us/articles/115005297709-On-which-wallet-can-I-restore-my-wallet-if-I-lose-my-Ledger-device

Note that they do not indicate Trezor as a compatible wallet but it is. Have tried restoring from Trezor and it works.

2) is ledger a good choice? Personally use it and have no complaints so far. Not sure why there are so many complaints on Reddit though...

3) can it have bugs? Yeap, hence the need to keep track of updates.