Should be 1-2" of preload to get ride height. If so, you're fine on rates, might be some room for improvement, but if you're too soft it becomes a floppy mess and G-outs suck. At 155lbs, you shouldn't really be able to move it more than an inch, since 155lb combined rate is about right on a buggy like that, especially if you put 4 people in it.
Ride height should retain at minimum 1/3 of your total travel. 50/50 can be better, so long as you're not bottoming excessively. If you don't retain enough down travel, the car falls into holes instead of the tire. That being said, if your car has 8" of uptravel/14" down right now up front at that ride height, your shocks might be too long. Not much you can do about that without spending money on shocks, and I wouldn't lift it much more than it is now since you'll get into shitty geometry on the suspension itself. How's the rear for ride height and available travel?
As for long/short tube, that can be different on different shocks, especially if someone ordered custom ones for some reason. Either way, the tubes adjust the suspension where they exist (between where they're welded to the body). Generally speaking, on a standard shock, the short tube is the big bump adjuster, and the long tube is the small bump adjuster. So, if small bumps feel "sharp", loosen the compression screw on the middle zone (or long) tube. If small bumps feel like the car is falling in instead of the suspension, loosen rebound in the middle zone. If it's bottoming to easily, turn the screw in on the compression side closes to the top of the shock (usually short tube). For "my back hurts" type moments, I assume most of your work will be in the compression side of things, but don't overlook how too much rebound can make a buggy ride like chit.