How long to cook asparagus on a BBQ

The chicken fat layer in the skin is flammable. As it melts, it drips out and down. If there is something extremely hot underneath it (like hot charcoal), it will ignite causing a flareup. Heat rises, so the heat and flame go back upwards to heat the chicken more, causing more fat to melt and drip. It is a self-reinforcing cycle.

To prevent the cycle from beginning:

• lower the heat level
• put a drip pan between heat and the chicken
• move the chicken so it isn't directly above the heat
• start with the side of the chicken with skin facing down, finish with it facing up

If you actually get the skin hot enough to catch fire while on the chicken, you're REALLY using too much heat.

See: How do you cook calamari / squid and avoid making it tough?

The principles remain the same for grilling or barbecuing: you want to cook the squid briefly so it doesn't toughen up, or slowly for a long time, so that the collagen dissolves to gelatin, making the squid tender again. In between is the rubbery zone.

The main issue is that many squid are not really large enough to place directly on a grill grate without danger of falling through, so you may wish to use a fish or vegetable grilling grate. You can then grill them briefly, over high heat.

It is probably possible to use low-and-slow smoking techniques (true barbecuing), but I didn't find any really credible sources or recipes, and I have never tried this myself. You could also grill the squid to get some smokey flavor, then finish by braising them (for example, in a disposable pie tin on the cool side of your grill, with flavorful liquid) for a long time.

Googling barbecued squid recipe will give you many recipes to try, with a variety of marinades and treatments.