I had a the 2hp 4 stroke Honda on the SC20, and it would push the boat 6 kts in flat water. I fabricated a mounting bracket that allowed the lower unit to be almost parallel to the tramp when raised. This worked well when sailing in up to about 12 kts of wind, but above that we started bashing thru the waves and it started to exert big forces on the motorandm mount. It was also difficult to motor in chop, because the pitching either pulls the prop out of the water or threatens to swamp the power head. On big air days I'd remove the motor and mount entirely and rely on the paddle if it shut off, which was substantially less likely than on the light air days.
I also had a lightweight, older two stroke Evinrude 2 hp on a Hobie 18 Magnum. It also did fine on flat water, but was a hindrance when waves developed. And 30 to 35 lbs hung off the rear beam of any cat encourages stern drag, which always needs to be compensated by moving crew weight forward. If you've got 2 adults and kids and a motor on a beach cat, you're pushing it pretty deep into the water. Avoid strong winds in these circumstances. Good luck!

Dave