1. No Third-Party Seizure
That is with bitcoin protocol, but bitcoin can be seized on custodial wallets and exchanges.
2. No Taxes
Assuming you are paid in bitcoin by your boss, you have to pay tax too.
3. No Tracking
Most people are using IP addresses and SPV wallets. If it is like that, tracking can be done.
Once Bitcoins are sent, the transaction cannot be reversed.
Yes, because the confirmation time can be fast. If the transaction is not confirmed yet, it can be reversed if it is flagged as RBF.
6. Bitcoins Cannot be Stolen
There are bitcoin wallet that has been hacked before and bitcoin was stolen, you have to be careful and avoid hackers and scammers.