Effect of reversing a pair, in cat5 cabling (e.g. swapping stripe and solid)

I believe that the difference between 5 and 5e is a more specific description of the twists per pair and twists per foot of each pair.

Cat5a and Cat6 further enforce the geometry of the pairs relative to each-other over the course of the entire cable and restrict the untwisted amount at the ends.

In practice, if it says Cat5, it is an old cable. "Cat5" hasn't been made in years, and any twisted pair cable suitable for use in networking (ie not cat3 or something used for a thermostat or lawn sprinklers) will be a Cat5e or better.

A true Cat5 installation is sufficient for gigabit ethernet. I've seen plenty of things labeled cat5 that are not actually up to spec for one reason or another, that run 100mb fine but don't work with gig.

A whole 1000' spool of cable would cost little more than the patch cables.

You shouldn't use RJ-45 on one end and punched-down connections on the other end if that's what you're describing. You also shouldn't use plugs on through-the-wall cables.

                          | walls |
switch ]---[ patch-panel <---------> jack-or-panel ]---[ computer


                          | walls |                             | walls |  
switch ]---[ patch-panel <---------> IDF-panel ]---[ IDF-panel <---------> jack-or-panel ]---[ computer

...and similar

where "]" and "[" represent RJ-45 and "<" and ">" represent punched connections.

Edit:

Here's the first example that popped up (no endorsement implied):

_{(source: computercablestore.com)}

Also, do yourself a favor and use service loops. The extra length will come in handy for changes, etc.