"storm control" is often difficult to get just right, except for blatant out-of-control cases such as a DoS attack.
If your switches support and enable IGMP snooping, this might explain "I have noticed high multicast numbers on certain ports on switches while others have none."
IGMP snooping should also limit where the multicast packets are flooded but you'll need an IGMP querier.
As to the possible source of high multicast, it might be worthwhile to analyze what the source of the multicast is. Perhaps some users are running some type of Ghost replication or a multiplayer game.
"Could this cause a latency problem if the collisions become excessive?" Yes, but very unlikely especially with 10/half connected printer when it's the only device connected to the switch's port with a printer's usual unidirectional data stream. Although later printer NICs are often faster, the printer itself might be the bottleneck, especially when using character fonts.
If your auto ports have configured themselves as 10/half for a 10/half device, no real advantage to manually force them to 10/half.
