Will I be able to use my debit card in Lithuania?
7 years ago I had no problems. I can't imagine it would be more difficult at the present time.
Of course. And make sure your card issuer knows your travel plans.
Yes. We've been to Lithuania three times for a month each and never had any problems using a BofA debit card or our local credit union's debit card. Enjoy Lithuania! And do what Frank says.
You should be fine. As was said, make double sure your bank knows your travel plans so they don't put a fraud alert hold on your account. Even then, keep your bank's phone number handy. If they do put a hold on your account, they won't release it until they talk to you personally - and then the reset usually hits overnight rather than immediately.
As long as you have at least one of these logos, Visa, MasterCard, Cirrus, and/or Plus, you can access virtually any ATM in Europe. The European ATMs won't charge you for the transaction (although it's not unusual for them to set transaction limits that are less than your bank's daily withdrawal limit).
Be careful to avoid Automated Exchange booths that look suspiciously like ATMs, but will charge you for an "exchange" transaction. Avoid anything with "EX" in the name and stick to ATMs with some form of Bank, Banc, or Banco.