Anything bad to place a via on a pad?
The industry term for this is via in pad.
It's not a problem when you hand-solder components.
It can cause problems during automated SMT assembly.  Solder, which was applied to the pad as a solder paste, can drain through the via and there will be an insufficient amount of solder to hold the part.


(Image came from this blog entry, which illustrates the issue.)

There are methods in which the via in the pad is filled with solder or epoxy.  That is done prior to SMT assembly.  That adds to cost of assembly, so the benefits from the via-in-pad need to justify that.

Related

older thread: Vias directly on SMD pads
article: Via-in-pad guidelines for PCBs