You can modify it if needed, lower it, change the seat, adjust the suspension, etc. that may help but I think the best thing to do would be to go sit on one at the dealership or a friends to be sure. Just keep in mind, it's a 500+ pound bike that doesn't have reverse. So you will need to be able to get your feet down at least well enough to walk it back.
Gonna be extremely difficult just as mentioned before. The busa is a heavy bike and its gonna be the small things like backing up or stopping on a hill that may get you in some trouble. I'm 5'10 200lbs and Ive cut a great deal of weight of my busa and its still a task at times to maneuver it in tight spots etc. Might wanna look at a liter bike and lower it and stretch it out. Seen a couple guys go that route and it worked out for them
1st generation Busa is only 475 lbs dry and can be lowered in about the same amount of time as it takes to change the oil. You just need a spacer kit for the front and different dog bones for the rear...both are inexpensive.
If you need to go lower, you can buy an aftermarket seat or have the foam shaved in the existing one.
I have no experience with the 2nd generation so it may be a bit more involved.
If you're looking for an ST bike that you can eat up some serious miles with, you won't find anything lighter than a Busa. Unless you're a woman with a thin build, its weight should not be an issue for you. Its weight is on par with some of the 500cc plain jane street bikes of the 70s and 80s. I have a 500cc Honda V-twin that weighs 70 lbs MORE than my Busa.
5' 2" here and extra round and I own and ride a Busa
To flat foot both feet you will have to lower it so much that riding it will be such a pain you will hate the bike because it will be bottoming out everywhere. Speed bumps even angles from driveways will seem like a mission everywhere you go. So I lowered it 2 " in the rear and 1-1/2" in the front I also shaved the seat to lower it even more, and I am about 1" short of flat footing the bike. I have still have room to lower the bike and not have major problems hitting the bottom of the bike everywhere, just been to lazy to do it.
You will encounter this problem with maybe every sporbike you want to ride. At our height the preferable seat height would be about 25-26" There are no sport bikes or even sport touring bikes with that kinda of seat height you would have to go to the cruiser bikes to find that kind of height. I acknowledge that the width of the bike at the seating area also affects the needed height. The wider the bike is at that area the lower the seat height needs to be. My Honda F3 600 cc bike was pretty thin I couldn't flat foot that either without modding the bike.
If you want a Busa and you are short you will be able to mod it to ride it, just remember as you lower it you reduce how much you can lean it, hard parts will scrape sooner ride accordingly.
As everyone else mentioned , you need to first try out the bike just to see if you comfortable sitting on it. It is a big bike. It can be quite a task reversing your bike if your feet are not substantially levelled to the ground , especially if the bike is parked on a decline/incline. Having said this , the bike can be lowered , seat changed plus you can pick up some riding boots with bigger soles to make it easier to reach the ground.
I'm 5'6" and have my Busa lowered AND have the seat cut...could have gotten away with just one of those mods and it would be comfy enough to flatfoot, so with both, I'm confident someone shorter than me could ride it. I have a girlfriend that is 5'2" and she rides/drag races a Busa, but I have a feeling she's all legs.
Best thing is to sit on a stock one and see how far you are from it being comfy, then see if you can find someone with a lowered Busa and feel the difference.
Your inseam would probably be more of a factor than your height. My inseam on my pants is 30. I'm in good shape so I can muscle the bike pretty well. I'm on my toes on the bike so for backing up, I just get off the bike and push it around that way. If that doesn't bother you and your in good shape the mass of the bike shouldn't be to much a concern. If you do lower the bike though don't forget about the kickstand. It can be awkward if you don't. By the way, the length of your arms may also be a factor for you comfort wise.
5'5-5'6 here with a 29"-30" inseem. As others have said seat and lowering will help. At a point you just have to accept that motorcycles are built for folks with longer legs. My current bike at full height (02 GSXR1000) I'm tip toed at a stop, this is after installing a cut down seat. It's doable but takes some practice. Lowered 2-3" on the 750 and I was totally flat foot.
heh... I could soo get banned right now so I'll just leave it as
mine is lowered 1.5" in the rear and I have no issues. My inseam is about 29". I also wear riding boots with a solid sole which add probably .5-1" of added reach. I have not had any issues on mine, its an 02 and I've had it since new. The weight of the bike is something to deal with though, if you dont have decent lower body strength you will probably find situations that cause you to become familiar with fairing pricing