There are only three things that will harm your cast iron ...
- Dropping it or banging it against hard objects It can be easily broken with just the wrong impact (I broke a leg off moving a heavy oven over a rock campfire ring,) yet I've picked up unbroken pans/ovens/lids that have fallen off a moving vehicle. It's not as fragile as tempered glass, but if you treat it with that level of care you will never have a problem.
- Extreme quick temperature changes Plunging hot iron into cold water or dumping a large quantity of cold food into a really hot pan has the potential to crack it.
- Not using it often enough Rust and neglect can be recovered from except in extreme cases
Practically
any heat source can be used with CI. I've used small alcohol stoves (takes lots of fuel), sterno, campchef stove, coleman stove, charcoal, top of a coal fired railroad stove, the edge of a blacksmith forge (keep it rotated), campfire, kitchen stove and oven (gas and electric), rosebud tip of an oxy/acetylene torch (at a distance to prevent uneven heating), a propane weed burner, and I've even used CI in the preheat cabinet of an asphalt crack sealer. The only place that I've thought about but haven't tried is on a glass cooktop (nervous about the cooktop, not the iron.)
Other things, like cooking acidic foods, can be mitigated and doesn't really harm the iron itself ... if you take appropriate precautions (wash & re-season appropriately.) The real part of CI that you have to care for is the seasoning on the pan. Just say NO to dishwashers, soaps/detergents, extreme heat, etc. because they will harm the seasoning but not necessarily the iron itself.
Do not fear trying something new. As long as it is within the range of temperatures appropriate for preparing food and will not contaminate the food itself, you are probably OK.