Pretty sure that is a 160 thermostat so between 160-180 should be fine. Higher than 180 you may be concerned. When I dewinterized this year mine was running a little hotter than usual. $60 worth of impeller and thermostat and an hour of labor in the driveway and it was all good again. You may also need to clean out the screen on the water line after the v-drive if there's any chunks in it.

The little red light disappears once you are in gear and past idle. I freaked out when I saw that on my first test drive AFTER I had already bought the boat. Prev owner told me that is totally normal. If it stays on then that's a problem. Did you notice it go off after you got moving?