1.) pwede ba ako gumawa ng another account sa bitcointalk, while using the same IP Address ?
Yes but for a good thing only like there's an indication that it's your alt account but if it's for bounty purposes, then it's punishable when you're using multiple accounts.
2.) Pwede ko rin ba siya i open at the same time ?
Yes, using incognito window
3.) mababan ba both accounts ko if ever i did that?
Possibly yes, the thing is, if you've done something wrong or any violations, both accounts will be banned.
4.) What if lang po " nag bigay ako ng merit sa other account ko , is that even possible or is it a violation ?
Yes, merit abuse.