Its possible to turn an equipment or an aura into a creature, but they cant stay attached to anything if this happens
On the other hand, both Esper Sentinel and especially Sylvan Anthem are going to be difficult to collect through limited since, even if you open the correct pack, they will only show up 40% (or less) of the time, which means you might need to spend wildcards to get them, even if you play a reasonable amount of Jumpstart: Historic Horizons limited
Earthbending Student could see play in a thematic deck or casual setting, but for competitive play, other cards may offer more consistent value
Aether Revolt (and all of Kaladesh block, for that matter) is particularly interesting in that it has a high number of artifacts compared to a typical Magic set
Skullwinder If you like a little more politics in your games, then consider leaving your Eternal Witness at home