I agree, I was disappointed to learn that I had to provide at least a minimal template.mf file even though every bit of information in the final generated MANIFEST.MF could have been inferred from the pom.xml. I would rather save specifying a template.mf file for when I needed to override the default behavior. Bundlor could really take a page out of Felix's maven-bundle-plugin here.
Automatically figuring out the appropriate versions for the imported packages from the maven dependency list would also be extremely helpful. It would simplify managing dependency versions so that you don't have to manage version information in two places (pom.xml and template.mf).
I would expect bundlor to determine the Import-Package version by inspecting the MANIFEST.MF inside the dependency, and if it is missing default to the maven dependency version.