Nonea
Specialist Cavalry Weapons could only be used while mountedYou didn't specify, but I'd think the 1h weapons with the power of 2h weapons should be limited to use while mounted if they're added.
Nonea
Genius ideaYou didn't mention ranged weapons. I can see how those (the 1-handed ones) could be used from a mount.
Nonea
The damage initially should be shared by rider and mount until the mount throws the rider. there would be an HP boost to the rider - that is to be expected.As for the mount/player taking damage, letting the mount take damage along with or before the player could give mounted players quite an HP bonus, made even higher effectively by allowing the mount to be armored. I don't know that having to heal the mount after it dumps you off (How? Stick it in the stable? Heal spell (too easy)?) would offset the HP bonus.
The mount can only be healed by time in the normal way, although possibly this could be helped if there is a food stack with you.
Also since this is a specialised mount there would have to be a limit to how much gear it could carry - I would limit it to enough for perhaps three weapons and a spare suit of armour.
I would expect the advantages to this arrangement would be offset by the difficulty and expense of doing it properly - as with other weapons / armour combinations, low level abilities and gear would be useable but not very effective. Training in what should really be a new skill tree would enable the experienced player to get something really effective.
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It's bad luck to be superstitious . . .Palta e decata, nan nec ilne matala.
When one goes on a journey it is not the scenery that changes, but the traveller