Do I need a special crimper for these connectors?

A standard wire crimper rated for the gauge you're working with will handle these. The connector size corresponds to standard AWG ranges, so your existing crimper should work fine—just make sure the jaw opening matches the connector barrel.

Do these connectors come with a heat source, or do I need a heat gun?

Connectors only—no heat gun included. You'll need a heat gun, lighter, or soldering iron to shrink the tubing after crimping. A heat gun is the safest and most controlled method.

Can I use these for battery or high-current applications?

These are solid for typical interior wiring, gauge cluster work, and audio wiring. For heavy-duty battery connections or main power runs, step up to battery terminals and larger gauge cable—these connectors are built for lower-amp circuits.