2) FTL travel is indeed possible. The Ceidwaid model is fuelled by a substance I've yet to name.
The substance consists of three elements:
The first is a drysŵr (power-gem) of any element related to movement (space, psionics, gravity, technically air.)
The second is a constant stream of energy being poured into the gem either directly from a Ceidwaid or capsules.
The third is an element of faith, this can either be a blessed, sacred or holy relic/icon or direct prayers. This dictates the speed.

Commerical FTL drives exist however they're slower and slightly more dangerous, as they involve slipping out of reality to use them.

Limitations include: (O for commerical drives, E for Ceidwaid drives)

Shortage of fuel (OE)
Power drain (E)
Bigger ships require more expensive drives (O)
Moving a fleet for warfare or commerce will require waypoints to be deployed, static beacons that act as a temporary motorway, a time consuming
move, however it ensures that ships do not end up going stray or missing their target (O)
For long journeys, multiple Ceidwaid of a movement based element may be required to sustain the drive.

3) In the mortal world, most magic stems from demonic influence. Resulting in very few being able to do magic more than a simple trick, such as aura seeing
and other such things deemed as pseudoscience. In the realm of Arallfyd (the magical realm) magic is much more common due to the abundance of energy
that resides there.

That being said, most mages and such aren't exactly powerful as they don't know how to master the nitty gritty. Due to their rarity, they're often kept off the
battlefields and kept inside nations as a support group. They run administrative tasks that very few people could do, such as checking for counterfeit
(no whipping up sixty gold bars here.), aiding in judical duties (ability to spot untruths and assist in finding evidence), transportation has remained virtually
uninfluenced, simply due to the stress of the job being damaging or even fatal to the untrained.