I had a 19' Lightning for a couple of years which is a bit similar to the Flying Scot. What a racehorse! When you get that boat (or the FS) up on a plane excitement is what happens. Of course you'll need winds more like 15 - 20 for that to happen.
I'm pretty sure you can get either the Snipe or the C15 to plane in the right winds as well.
The nice thing about a small dinghy sailor like a Lightning, Flying Scot, Snipe or Coronado 15' is that there is not a whole lot of maintenance to do - unless something breaks.
You did end up buying the Coronado 15', no?
CORONADO 15 sailboat specifications and details on sailboatdata.com
They were made by Catalina which is still in business. Not sure if you can still get parts from them for this boat though.
I suspect you will enjoy the C15 but I am sure you will really like the FS once you pull the trigger on that.
Some folks start out learning sailing on 30' + keel boats and seem to do fine. My opinion is that it is good to start out learning on smaller sailboats like the ones you are considering. The FS would also be a good 'starter' boat - it is really your call.
I worked my way up from a Sunfish through Snipe, Lightning and now Tartan 27'.