RE Canals, I think a good way to limit them is by having a water tile proximity requirement of say 2 and can only build them in own your borders. That would stop most spam and only allow canals linking water bodies 4 hexs apart. As Machu Picchu has a 2 tiles of a mountain requirement i figure the mechanic is already there to build up from for canals.
RE Outposts, I love the idea but would personally allow new city founding/border pops to take control away from the outpost owner.
RE Outposts, I love the idea but would personally allow new city founding/border pops to take control away from the outpost owner.