Hi,
The number of variables you can have depends on the amount of RAM in the actual PIC you're using and on the size of the variables you declare (BIT, BYTE, WORD, LONG). For example the 16F877A has 368 bytes of RAM, PBP uses a couple of those for its internal use (~30 or so I think) and the rest is available for you to use. The compiler will throw an error if you're trying to allocate space that aren't available.

It quite common to have a couple of "general purpose" variables used in FOR-NEXT loops etc. You don't have to have a separate one for each loop but obviously it depends on what it your doing.

/Henrik.