I put a Daiwa Fuego 300a spinning reel on a Abu Veritas Medium action rod. The reel seems tight, but there is a open space between the reel and the rod. Is this ok ? Its not a big space or nothing but you can see daylight through it.

I don't think it will make a difference. You can wrap the reel foot with electrical tape to close the gap.

As long is it dont hurt nothing i dont care, the reel is on there pretty tight i just never came across this.

The only thing i would be worried about is if there is a loss of sensitivity (more contact between the reel foot and rod = more sensitivity). If you are not having problems with the sentitivity you should be fine

The gap comes from the split reel seat they use, it has no insert, which is hollow and doesn't contact the blank fully any how so there is no adverse affect on sensitivity. If it feels good to you it is fine.