I'm not sure those questions give a meaningful metric, in your case.

Not knowing the intricacies of your program at this point, all we can do is offer guesses based on instinct and experience. If there are 15 to 20 database calls per iteration, my gut tells me that's your bottleneck. (It's possible that there'll be a really poorly coded algorithm, but that's a lot of database work.)

As for the lines of code in general, if you're not swapping, you're probably okay. The important thing is how much work you do in each iteration, not how big the program is overall.

You'd have to go to a fair bit of work to make Perl re-open and re-compile each module each time you want to use it, so I doubt you're doing that. (It's doable, yes, but you really have to want it. There aren't many good reasons to do that, either.) When your program starts, anything used is compiled. Bang, you're in business. As it runs, anything it must require is compiled, once, and you're still in business. You pay your money and you get your hand stamped automagically.

Of course, code size does matter in some cases. If you utterly destroy locality of reference with frequent, long branches, you'll take a performance hit. Then again, Perl's not really your language if you're worried about processor pipelining. It'd be a pretty Baroque program to do that, too.

Does that make sense?