Well Silva,

your map has a great potential, I think. The area and scale is a big pont. When your landmasses are continents, your map is showing a whole planet (more or less) and therefor your landmasses are very fringed I think. There is bay to bay and fjord to fjord. Just look at google earth for example. When you see all continents there, you wont see to much fringing. Even the some hundred fjords in Norway or the slender build east coast of the USA looks quite calm and smooth there. But of cause, itīs your world and your decision.

To the rivers: Itīs right, you need more rivers. Itīs good to have some six or seven large rivers spread on the world, like Nile, Danube, Ganges, Mississippi, Amazon or something and some minor rivers. Donīt spread them to regularly over the masses, some should be closer together some more far away. And be carefull with them, the river police is watching you. Crossings like chick marked in red should not appear to often. In this scale of map, itīs no problem to have one or to of this crossings because focussing in would tell us, that those rivers are not flowing opposingly but curved together in the right way

The Mountains: Even the mountains should be spread across not to regularly and they better were of differnt area, not to similar. You need (and alreday have) some large Mountain-areas, some medium ans some smaller. Choose symbols for Mountains of different size, that would make your map more realistic and interesting.

Maybee those ideas could give you some direction - even when your direction seems to be good as it is