Some Suggestions

[TactiCol]

I'm finding the cavalry momentum a bit messed up on gradients. Horses can almost come to an emergency stop just touching the bottom of slopes (even if you had no intention of going up the hill). I'd love to see this improved.

A fatigue bar for spam swinging.

Slightly less fall damage on horse jumping (Courser)

Some type of formation arrangement on spawn.

Flank left, flank right, Guard left flank, Guard right flank and Look behind you voice commands.

Better spawn points

Some of the poorer maps removed from rota on EU1 

A cap on the number of items eligible for repair

Will add more suggestions to this post as I spot different stuff in game.

[slothscott]

A fatigue bar for spam swinging.

Flank left, flank right, Guard left flank, Guard right flank and Look behind you voice commands.

I think swing spamming has been resolved in the recent patches and so a fatigue bar need not be implemented.

regarding voice commands, I don't think you want too many commands although those commands you've mentioned seem tactical enough. I can imagine someone saying "Look behind you!" in the heat of battle to have several people quickly spin around to check their backs - would be quite amusing.

[Vexus]

I want a voice command "Look out!" or something near because not everyone gets I'm whistling to warn them.

[TactiCol]

I want a voice command "Look out!" or something near because not everyone gets I'm whistling to warn them.

Same reason I suggested the look behind you voice command too.
I whistle at people too right before I see someone stick an axe in their rump. It rarely works. Usually it's met with more whistles.