Not sure I grasp the tank issues, but I would danged sure not pass up a chance to move to induction over gas. Having used both quite a lot, there is no comparison for me, but YMMV. There is a long and fascinating thread on this topic over at Appliance board. Will try to post it below.

Here is a link that might be useful: Induction v. Gas

We had to move the oil tank from in ground to in house at the old house and neither the oil burner nor the tank smelled. There is clearly something wrong if it's smelling.

You would have to look at both propane and oil in your area to get a true cost comparison to see which would be more efficient for you to use.

We chose to not do either in the new house but went with geothermal which has proved to be very cost effective. And we love waving at the oil trucks as they drive by our house!

I too would vote for the induction cooktop regardless of the fuel issue....it is superior to either gas or electric, IMHO.

I would contact a reputable furnace repair place (your oil delivery should have recs) and talk through the issues with the smell. How old is your furnace? Is this project creep justified?

You will need to get your local rates for all of your energy sources you are considering. Also, your savings depend on your weather patterns, which might be quite different than mine.

I like my gas stove, and I like it that I can light a burner with a match when the power's out. I have heard induction is pretty cool. If I were significantly over budget, though, I would not feel good about buying the induction.