I'm sorry but those paths are disgusting. They are ridiculed with, quite obvious, tile errors.
There aren't any tile errors that I can see (given the path system in R/S/E).
However, Wind~, I'm not a fan of those little indents you used. The flowers are also a little too abundant in my opinion.
It's hard for me to comment on the tree shadows as I'm not familiar with the correct way to do them in R/S/E but by FR/LG standards, they are just awful D:
As for tall grass placement, again I think you used too much. The player is pretty much guaranteed to run into a wild pokémon in each patch. Also, that optional patch is too close to the southern patch; I think it'd look a lot better on the west side of the map, so as to give all three patches some space in between (unless, of course, there is a map connected to the left of this one. I assumed, since it was Route One, that there were only two connections, those being north and south)
Eh, not much else to comment on. The concept of this map is pretty simple so there's not a whole heck of a lot to talk about. It could be a lot better though with some touches here and there. It just looks a little bland right now. Try to spice it up a bit, 'kay? :3