No, it does not need to be flashed.
You need to use either a MK4-Mini or a MK4.
It's gives you an option to either boot from Slot 1 or Slot 2.
Select Slot 1, then it asks you to eject the Mk4-Mini or the MK4 and insert in the Slot 1 solution flash cart that you have and it runs fine.
That's why I'm asking if it is possible to run FlashMe V7 from a Ds Link or any other Slot 1 solution.
I'll have a look when I get mine, coming this week apparantly.
I imagine it should work but as not all homebrew seems to be working it will need to be tested.
Maybe Devs, who did a review here can test it before me.
Yes you can use a MK4 to boot the DS-Link and then run flashme.
No DS-Link does not run every single DS ROM. Compatability seems just slightly below the slot 2 cards, Tony Hawk won't run ATM.
I'm sure the compatability will be just as good as the big name slot 2 cards within a few updates. As long as they keep updating it