Although I do not know much about the Tridentine Mass, here is what I know based on your questions:
1: The Tridentine Mass is the Mass before Vatican II. The basic sections of the Mass arre the same only different format. Most of it is in Latin. This may help you on the flow: unavoce.org/ttmass.htm (If anyone has a better site for the structure, please post it).
2: Yes, providing:
*]It is not performed by a group not in communion with Rome (i.e. the SSPX). For valid and licit places celebrating the Tridentine Mass, check: latinmass.org/directory.html
*]The same rules about being in a state of grace.
[/list]3: Yes it is.
4: We can attend all rites as long as they are in communion with Rome. This includes the Eastern Rite Catholics (as opposed to Eastern Orthodox) such as the Byzantine and Ukranian Catholic.
I hope this helps.