Lake Wicwas is correct, although there may be other spellings in common use. See:
www.lakewicwas.org.
Googling on Winnisquam, I see ample number of references with "Lake" before and after the name.
This map, from 1891, shows "Red Hand" island east of Sleepers. Bizer's site (
http://www.bizer.com/winislan.htm) says the island now is Treasure Island, with (AKA Redhead). That old map is on one post on this old thread, which also discusses Red Hand vs Redhead:
http://www.winnipesaukee.com/forums/...ead.php?t=1650
I'll leave the "points" to others.