How about a Sentry Promotion for Scouts and Explorers? They really need that promotion. That'll give you enough warning to avoid danger.
IMO they're already a decent unit if used intelligently, especially now that W3 is available to them as muxec also notes.
Woodsman 3 to recon units coupled with larger bonus against enemies makes sub-super healers to0 easy to get for hunting-starting civs, IMO.
Other changes are reasonable, well done. I guess we should start a SG to test the changes sometime in the future.
Is it a problem that hunting civs get a slight boost? They also get archery earlier than other civs and now that archers have an extra 25% vs. axemen it could be argued this is another boost to hunting civs.
Scouts won't usually get W3 without upgrading it to an explorer. Non-hunting civs will just have to try a bit harder, by building an explorer with 5xp to get it.
IMO the way GGs are used as super medics is really weird. The idea that a combat-hardened war veteran is attached to a weak unit to become a medic is kind of funny.
Anyway, if allowing recon units to get W3 a bit more easily helps to dissuade people from attaching GGs to scouts or W3 melee units, then all the better IMO.
As for starting a SG, it's up to you but I wouldn't personally recommend it just yet. There's still a few things I think need changing that we haven't addressed yet.
At this point I'm still looking for people to hack it to pieces by way of criticisms.