VPIP stands for Voluntarily Put $ Into the Pot, so it's not 14-18% by default.
If the pot is unraised and you're in the BB, your involvement isn't voluntary. Same goes for whenever you fold from the SB.
30-35+ is usually considered fairly loose. 40+ is very loose. 50+ hands gives you a basic idea.
RFI means raise first in, meaning the % of the time a player raises after the action is folded to them.
As a general rule, most players playing hold'em these days cBet too frequently, though very few fire 2 barrels. For me personally, I've always included fold to flop raise and fold to turn bet in my HUD to see how often my opponents give up after a single barrel. This stat takes a while to build up (a few hundred hands minimum) but can be quite telling and help you take down a lot more pots without showdown.