How do we know oil is finite? The Earth makes oil on its own, does it not? Does it not make so much oil that it flows up through the ground and into the seas? (Serious question, I haven't researched it) I know we always say "well someday that oil is going to run out" but is it really? How much across the globe have we yet to discover, tap, use? I frankly don't give a damn about what happens 300 years from now, I guess I'm a bad human.
Petroluem and coal are just end-decay products of organisms who were trapped under sediment in oxygen-free conditions and were then subject to geolicic pressures and stresses. The thing is, formation of oil and coal takes millenia if not eons to happen, and at the current rate of consumption, we will "run out of oil". The bright side is that we can do with technology what it takes the earth millenia: crack biomass into hydrocarbon chains (biofuel). Done using algae or other renewable food sources, it could provide a lot more sustainable source of energy.
The question about oil vs. other forms is very complex, IMHO. Oil in and of itself varys from easily-refined "cheap" (light sweet crude), to more diffcult to refine (heavy sour crude). The quicker we use up the cheap oil, the more expensive oil will be in the long run because the heavier and sour oil will be more expensive. One way that can be mitigated is by mixing biofuels with oil right now to lessen the impact, and possibly moving to power sources that don't rely on petroleum if it can't be helped. i.e. powerstations and their relative immobility could be nuclear, solar, tidal, geothermal, hydro, or wind powered to some extent which again, lessens the oil need impact. Transport, would require a portable, high energy density fuel, so would be more useful for petroleum and biofuels. To me, it's not so much a question about 300 years from now, but if we're paying farmers not to farm, and that arable land can be converted into growing biofuels, whihc in turn could be mixed in with gasoline and keep the cost a bit down and our need for foreign oil, why not?