Are there any benefits to the Melee dice pool of a character when attacking from a ridden beast? If there are, I'm not seeing where in any book they are listed.

Probably not, in fact i would consider giving setback due to the extra motion, but the Beast does have their own attack that could be used.

I would probably ask for the Player to make a Survival check as a Maneuver to control and direct the Beast, allowing the beast to perform a Maneuver and an Action (strain for an additional Maneuver like normal). Not sure the difficulty, but probably Hard, its a significant bonus.

Well, the Mon Calamari energy lance allows you to use the animal's Brawn to add damage to the attack. That's one possibility.

If there's any mechanical advantage to riding a beast in combat I imagine it's more along the lines of spending one manoeuvre (Fly/Drive) to get your mighty charger to spend two manoeuvres moving. Which technically leaves you with one "free" manoeuvre that round.

Personally I'd also be inclined to give a boost die to the attack of any character astride a mount that's charging a target.

None of the rules in SoT modify the rider's attacks. They just allow you to move faster by using the mount's speed instead of yours, and perform certain nifty actions like the climb/jump or push, in addition to attacking with any of the creature's natural weapons. All of those take a Survival check. It does say the rider may make his own ranged/melee attacks, with no (dis)advantages listed.

So far the only weapon I know of that does anything differently is the Mon Cal lance, which was already mentioned.

As far as adapting some other weapons to be similar, The idea of any "lance" type weapon gaining the creature's brawn added to damage makes sense, as long as said weapon is based on the momentum and force at which it connects with it's target. This of course would be up to the GM.

And on this note, I really want to play a Seeker: Pathfinder with a saber pike and a varactyl now.

None of the rules in SoT modify the rider's attacks. They just allow you to move faster by using the mount's speed instead of yours, and perform certain nifty actions like the climb/jump or push, in addition to attacking with any of the creature's natural weapons. All of those take a Survival check. It does say the rider may make his own ranged/melee attacks, with no (dis)advantages listed.

So far the only weapon I know of that does anything differently is the Mon Cal lance, which was already mentioned.

As far as adapting some other weapons to be similar, The idea of any "lance" type weapon gaining the creature's brawn added to damage makes sense, as long as said weapon is based on the momentum and force at which it connects with it's target. This of course would be up to the GM.

And on this note, I really want to play a Seeker: Pathfinder with a saber pike and a varactyl now.

With a FR 4 as well, so Seer as well.