PT 709 slim...Need Advice/Input please!

Welcome to the forum, and the "709 club"!

First, be sure you strip it and clean it thoroughly and lube it, this also includes stripping and cleaning the magazine(s).
Rack the slide as many times as you can stand it, and load the mags full up and let them sit for a couple of days.
Put at least 200 rounds through it for it to settle in, then test fire whatever SD ammo you will be carrying to ensure flawless function when your life depend on it.
There are a few aftermarket add-ons that are available - head on over to the 700 section in the Gun forum, and wade through the threads - I would almost bet that almost all of your questions have been posted on at some time recently.

The grip extensions are something you want to think about. Will you be carrying this "deeply concealed"? If so, know that the extensions can make this more challenging, due to the longer grip length. Also, practice a LOT with the extensions, as sometimes these can cause feed problems due to the pressure applied to the mag by your pinky.

Oh, and don't forget to show us your pictures!

Welcome - I've got a 709 that I pocket carry most days. The only change that I've made to the gun was to replace the front sight with the TRUGLO universal big light tube and it helps a bit. Many will agree that (as rclinton suggests) that AT are the best aftermarket sights made for the gun. They are on MY upgrade list for guns that I own. Some have more trouble with the stock 709 sights than others.

Wino is also on the money as usual - don't try and make the 709 into something it is not - as TXEirc even a change as small as a pinkie extension can have negative effects on performance (yes, some guns need fine tuning to shooters hands).

My .02 on lasers Crimson Trace is that they are in (or own) the top tier of laser sight products. I had one on my front of the safe HD gun for about 3 years. The more I trained and competed in action shooting events the more I realized that high speed shooting and decision making would pretty much make the laser useless for me - looking for a red dot on a farther horizon was not practical. Watch the CT videos - they will make perfect sense and many DO swear by them (and other laser products) I do love their grip actuation - no time wasted looking for a switch! That said, I sold mine and bought a front rail light. Yes, there are grip styles that allow for a remotely held light and I also subscribed to that school for a while. I now believe (based on tests and training) that having both hands on my gun in CQB or attack scenarios is my best option.

Food for thought. Send a range report M8!!