I am still pretty slow at some words especially those with one or more rolling "R"s. When speaking, is it better to skip the rolling for the sake of conversational speed, or shoud one try his best at proper pronunciation even if the speech gets very slow?

I'd opt for #1 while continuing to work on rolling.

I know this is the Italian Lang Forum, but here's a Spanish phrase with which you can practice rolling:

Rapido corren los coches del ferrocarril.

All of the Rs are really rolled in that one.

Still do not forget that many italian don't roll their "R"s. Especially in Emiglia there are whole reas (for instance the northern part of the Parma province) where the R is NEVER rolled while speaking in Italian.