Hey, there is still 7 weeks of airdrops left so you still have time to join in go to https://www.deeponion.org/airdrop.html to find out more.
Yes there is Linus wallet available, you can purchase $Onion at number of exchanges out of the most popular ones Kucoin or Cryptopia come to mind.
No you dont need to use TOR its integrated with tor already (it also has Meek and OBFS4 in case you need to use it in countries that are not pro crypto :))
Stealth addresses (Deep Protocol will be launched soon)