I am now ready to do what seems to me to be the most intimidating step of the building process so far, cutting out my hatches.

First I have a few questions: (Honest this is not avoidance)

The deck is sealed and glassed(4oz) on the inside, raw okume on the outside, I will be cutting from the outside. I will masking tape the outside before I cut.
Should I seal, and/or glass the outside before I cut or not?

Should I set the jigsaw to cut with a rotational motion or straight up and down?

The saw, Bosch, has a small clear plastic insert that fits closely around the blade to reduce chipping on the upstroke but if I cut with a blade that cuts on the upstroke am I asking for trouble? It seems to me there would be more tear out if I cut on the downstroke but I could mask underneath.

Could some of you woodworking brainiacs help me out?
Thanks.

Yours nervously,

Ken