Welcome to CS Steven,
Yes it is ok to fill the boiler by running water through the steam wand.
The process of steaming empties the boiler.
Hitting the brew switch or hot water switch will fill it.
As long as you hear the pump running the boiler will be filled,
Its a very good habit to get into but has the added bonus that it will bring the system temperature [following steaming] back towards brew temperature.
I find it useful to give the group head and pf a bit of a clean too.
I also suggest that each morning when you turn on the machine you give the steam valve a TWIST to tighten it.
This will stop any drips.