Dermarolling is not recommended with serious cases of Rosacea because there is chronic inflammation involved in Rosacea and since dermarolling with long needles causes inflammation lasting up to several hours, it could potentially worsen Rosacea, just like excessive heat, cold, strong wind, acid peels, sun or any other source of potential skin irritation. However this is highly individual and what worsens Rosacea in one person doesn't worsen it in all Rosacea sufferers.
Dermarolling the scars three times is not enough to obtain satisfactory results. You should certainly continue using your dermaroller.
Single-needling is the most intensive scar treatment.
However, Genesis laser uses infrared energy that warms up the dermis and stimulates collagen. The laser light is also absorbed by pigmented clusters in the skin, this heats them up and thus destroys them. The problem is to find the right settings to be effective but not overdo it. You have to targetedly destroy the pigmented tissue or diluted blood vessels but unfortunately sometimes the heat destroys too much tissue and you end up with pitted scars. These scars could be quite deep and they might even be wider under the skin than on the skin surface. You describe them as shallow so hopefully, they are shallow. I have found a similar case here (posting #4):
https://http://messageboards.makemeheal.com/laser-treatments/damaged-yag-laser-and-laser-genesis-for-rosacea-t110505.html You should continue dermarolling and definitely give the single needles a try but do a test patch on one scar first. If your scars are getting wider in deeper layers, needling will uncover those deeper layers and make the scar look temporarily bigger. As you continue needling, it should slowly fill up.