The necessity of or lack of heat within compost has been hashed and rehashed countless times. People should lose their union cards for implying heat is required to make compost. About the only way to maintain heat is starting with a very large bin(equal to about 200 gallons or 1 cubic yard) and have a constant supply of nitrogen. Don't worry about it,turn/mix your material once or twice a week and keep it moist.

One of the main problems with trash can sized bins is the build up of moisture. I've never used a can, but it seems to me that having as many holes as possible, without damaging the integrity of the can, is nothing but beneficial. Open air piles have unlimited access to air. Getting oxygen in, and excess moisture out, is going to keep the conditions optimal regardless of the temps reached. You can always add moisture if it gets too dry, but I've never heard of that problem in such cases.

Certainly air and size both matter as does the amount of moisture.

As well as the mixture of materials and the freshness of the high-N material. If you add bits and pieces over time, it will not heat up. If you make a balanced batch all at once, even a garbage can may get warm for a bit although it's ultimately limited by the size.

As for holes, I don't know the distance that air can diffuse into compost from a hole, but it's probably a few inches. Spacing them out evenly around the bin is your best bet.

The bacteria that digest the material, mesophilic and thermophilic, require a fairly large amount of air to function. The number of holes in your trash can would not be enough to be very effective. You would need about 50 percent of the can drilled out.