Is there any risk of having your pupils dilated too often (with dilating drops) in a short time period?

Dilation : Dilation is only a risk if you have narrow angles (rare but can throw you into angle closure glaucoma) or keratoconus (uncommon but dilation can cause permanent pupil dilation in few). Otherwise risk is very low.

No: In an earlier century European women would dilate their pupils as a beauty measure. The popular name for the plant extract containing atropine that they used is "Belladonna". Italian for "beautiful woman".

Not that I am aware: Drops that dilate your eyes are a class of mydiatics. They are sympathetic stimulating drugs that act locally. I am unaware that recurrent applications are necessarily harmful. I suppose there may be a risk for acute glaucoma in the right person.