Q: Dust

Yes, dust tends to accumulate o cooling surfaces and periodically the side cover for the silver tower Mac Pros and the cylinder for the newer trash can Mac Pro should be removed and inside cleaned of dust. Vacuuming can cause problem due to static electricity building up and blowing seems to be preferred.

Just stick to cleaning the exterior >  Cleaning your Apple products

Apple MacBooks move only a modest amount of air over time, and do not generally need to have their insides cleared with compressed air.

Mac Pro models (silver tower and dark cylinder) get very hot and have to move a lot of air over time to cool themselves. Especially if placed on the floor, you will need to blast out the dust with compressed air, at least as often as annually. Use your own judgement about how often.

As lllaass says, the tools on domestic vacuum cleaners can generate electronics-killing static charges long before you feel a Zap from static discharge, so if you vacuum, be sure to use a vacuum specifically designed for working inside electronic devices.

The connectors used inside your Mac would be described as providing "gas tight" connections. There is essentially NO risk that you will force dust into any place that will cause trouble by using ordinary air from a can or small Utility compressor.

Blowing very high amounts of air into the cooling fans could spin them faster than they are designed to run, and cause damage. So be careful not to  spin the fans excessively while cleaning.

Launching the dust airborne and out of your Mac makes a filthy dusty mess of wherever you perform this operation. If you do it inside, your spouse may confine you to the dog house for a long time. Be sensible and move your Mac Pro to a place where dust is a "don't care", such as the garage or outside for this operation.