1. My list might include such luminaries as - Big Game Hunter, Botanist, Zoologist, Cartographer and then with guest expeditioners Military Observer and Geologist (government provided).
2. Small, definitely. More vulnerable, so more fun,.
3. Re-finance, don't really know what this means. But financial backing could come from government, private investment (maybe from one of the adventurers) in return for various exploitation rights, Christian societies (providing spiritual guidance to the poor savages) or other charitable organisations.
4. Government representatives are very interested in military or mineral exploitation and want to accompany your expedition with a minimal complement of personnel, so as not to 'officially' be invading ... yet!
5. Airship to get close, then some sort of meteorological vagaries or rocks offshore or something makes things difficult and the players then have to downgrade to smaller sea vessels (maybe even sailing). This will help to make them feel cut off from 'civilisation'.
6. Nothing that works properly! An over-confidence in the reliability of a new wonder-device will add to the tension when the magnetic field (or something) of the island prevents it working properly!
7. Dino-proof stuff.