i'd try a diamond cutoff wheel on a dremmel. occasionally we have to make kevlar parts at work, and the machined edges are definitely not as pretty as the carbon fiber parts.
Give this a try:
Prep the mold with a good waxing/wiping then apply the PVA and let it get nice and dry.
Mix up your epoxy. I wix mine for about 1 min and that's it. Yes, more may be better but so long as it's mixed, it's mixed.
Apply a coat of epoxy to the mold then let it sit for 10 mins or so.
Take clean brush (I use those cheapy ones from Home Depot), pull on the bristles over and over to be sure you remove any loose ones.
Then, gently and with only the weight of the brush, drag the brush across the surface of the epoxy to remove all the air bubbles. You'll do this for "a while". Drag, let it sit for a few mins so bubbles can work themselves to the surface. You can also poke at the bubbles with a pin.
Now the fun part: wait for the epoxy to start to set up... a little.
What you want is the expoxy to setup enough that you can touch it and leave a finger print but have none stick to your finger. You may want to prep a "test" part so you have a control environment and aren't messing with your production part.
Then, once the epoxy is set up like this, gently but firmly, press your first layer of dry fabric into this "clear gel coat". BE CAREFUL as you do not get to pull it off, move it around, etc. If you do, you pull this initial layer off the mold and you'll get voids, etc.
Once you have the layer pressed into the epoxy. go do something else while it cures a bit.
Come back in a couple hours and wet out the layer in the mold and add your remaning layers, let them cure, etc.
This appoach should give you a perfect, no pin hole result. And you don't even have to bag.
Again, this is just one approach to composite layup. Maybe it'll work for you, too.
Best of luck...