Is it possible to stake with the wallet protected by the password? Is there a possibility to open the wallet only for staking and keeping it secure?
yes
Great! I've just transferred a few thousands of masternodecoins which I've bought from exchange and after a few hours I've already got 6 newly mined coins. A promising beginning.
Yes, running a masternode is worth it. My masternode server is running some days now and I can't hardly wait to look into my wallet every morning to check how much I have earned while sleeping. =)