So the broom itself is capable of flying for 9hrs a day and can move at 40ft with 200lbs of weight on it...
My Ranger has +16 in fly checks (if need be for this item) and weighs a total of 180lbs with all of his gear. He's using a ring of invisibility and boots of speed with Improved Precise Shot.
Am I actually capable of using this thing as a 40ft flying mount? My goal is to use it to get to partial concealment, fire off a full attack (3 full BAB, 2 not at full BAB) while invis/stealth and then use that partial cover to assist in getting away/re-invisibling :3. It would also give me the ability to maneuver into better positions to assist my party as well as giving me the ability to get into heal range of wounded allies and heal them while invisible.
My Ranger has +16 in fly checks
Does this include ranks in Fly?
"You cannot take ranks in this skill without a natural means of flight or gliding. Creatures can also take ranks in Fly if they possess a reliable means of flying every day (either through a spell or other special ability)."
Here is SKR saying the rule is to prevent someone from suddenly becoming a master of flying when he learns the fly spell. Then, much more recently, here is SKR saying, unofficially, that you should be able to take ranks before you can even cast the fly spell.
YMMV, but clear it with your DM.
My goal is to use it to get to partial concealment, fire off a full attack (3 full BAB, 2 not at full BAB) while invis/stealth and then use that partial cover to assist in getting away/re-invisibling
Only your first attack will benefit from invisibility, as the spell will break as soon as you attack. So sneak attack/denied dex/+2 is only for one attack.
What is granting you partial concealment? (Other than being invisible)
To be fair the character was a the pilot/captain of an airship for quite some time, it's all fluffy back story jargon, but it does essentially fit. The bonus would actually only total about 5 ranks into the skill, +8 from Dexterity, and +4 from the broom being able to stabilize itself (so a total of +17 on fly checks). I'll run it by them though.
As well, the way that the DM is working it, whenever a character is behind an object that would essentially equate to "poking out" to take a shot, it's partial concealment for both parties (the enemy gets partial, because los is somewhat blocked and so does the player).
Essentially it's like
....................E
|------|
|TREE|
|------|
....|-P|
Where E is the enemy and P is the player.
As for the invisibility stuff, I know that I only get it for the first attack, the first is the most important though with the Many Shot off of my +1+3Might Holy CompLong.