In this sentence Romae is not a dative but a locative. The locative case is only used with names of towns (and a few other nouns), and by itself it signifies "in" (without motion): Romae "in Rome".
If you want say "in" with another type of noun, you must use in and the ablative case (not the dative): in urbe "in the town".
Be careful, it's not "conjugated", only verbs are conjugated, there are as many conjugation in Latin than personal pronouns ranks (1st personal plural, etc...)
For words, the ending changes because of declension, and there are 6 Latin cases. They don't change according to the subject or personal pronoun, but according to the grammatical role in the sentence.
Not only "ego", but all personal pronouns subject are optional, or it mean you insist on the "who".
The pronunciation gives me the creeps: Liwia, uniwersitates etc...
Well it means “multiple” really.
Context in a sentence would help you determine if the author was trying to emphasize that there were quite a lot of some thing or just some random plural number.
There are other words to be used to be more specific. “Several” is “nonnulli, -ae, -a” which is literally “not none.”
Because that translation changes the case of “Rome” and “many universities” and uses a different verb.
It might stay relatively close to the idea of the sentence, though it does stress him. It also changes the vocabulary and miss uses the grammar. In a language course, early on it is often useful to stick to a more literal translation.