Yes I mean random production, the can still be set in the mapeditor of course. Currently they can be randomized as part of the players starting units though. Depending on how we change the seacreatures I think it would make sense to remove them from the starting units as well.
With that change you will now need to prevent players from buying Sea Creatures in cities that are not right next to the water. Otherwise players are going to do so and not realize they can't move their units and find they are screwed.
Yes I suspect you are correct. Lets evaluate this change for a bit before I update the city-buy-unit logic. No need to do the extra work if the change sucks
Hard to know how penalizing it's going to be to not be able to move sea units.
I can say this much. On the Small World map I was *this* close to buying a Sea Serpent on turn 1 for my capitol in our team game. If I had, you'd either be re-doing my capitol production or undoing the no move on land change because I am land locked by 1 square.