Q.Offshoots Of A Different Kind Are Growing Through My Japanese Acer. Should I Remove Them?

Certified GKH Gardening Expert
These are suckers from below the graft point. They are a completely different type of maple than the Japanese maple, as this tree is grafted to a different maple's rootstock.
Remove the undesirable root stock, since it will eventually kill off the desired portion of the tree.
You may need to address some issue that the tree has that is causing the suckers to form. This can be overpruning, or disease. The photo is not close enough to the tree to tell.
Here are some articles that will help:
https://www.gardeningknowhow.com/ornamental/trees/japanese-maple/japanese-maple-care.htm