[susan53]

1. No - the verb is wrong. As you say, there's a clash between the verb fprm (present) and the concept of "first" which suggests you are only talking about the past. You would have to say :

KJ opened her first gallery in Japan. That puts the event (the opening) firmly in the past, so the verb form is automatic. ot you could say :
KJ has a gallery in Japan. This was her first gallery, though she now owns three...

2. Here you could use either "is" or "was". it depends what's in the speaker's mind. Are you thinking about the moment that she decided (The name was taken...) or the fact that it is still called that (The name is taken...)

3. Use the possessive : Its name rather than the name of it. It's more natural sounding.