There should be foot braces for each paddler, check the manufacturer's web page to be absolutely sure.

It would work for either, just be sure to rinse the salt water as well as any sand, grit, gravel, or gross nasties out of it before you store it. The biggest drawback with it in open flat water would be that it will catch wind like a sail and can become hard to maneuver...

Generally speaking, ocean-going kayaks are designed to be long and narrow for the sake of following a straight line, and speed. This kind of inflatable boat has a huge amount of surface area above water opposed to what's below so it will be tossed around by any amount of wind you'll encounter. Also probably won't be the most comfortable for long periods of time out on the water. There isn't really anything to "apply" to make a boat an ocean kayak, it's all about the design.

You may be able to get something custom fit at a local shop, however there are other boats out there that come designed specifically for a rudder. There are a couple other considerations when installing a rudder aside from just mounting it on the back. Take a look at a P&H Orca. Or possibly a sit on top kayak specifically designed for fishing. Sit on tops are generally much easier to fish from because they are more stable and cannot easily sink if overturned. Just climb back up and keep going.

The outer face (the part with spot for lock and says "Thule") pulls of with a little bit of brute force and ignorance (screwdriver?), then that reveals a built in hex key that should unscrew the rubber strap.

Yes they should fit on the factory rails.

Those mounts should fit your factory rails.

Yes you can use MSR fuel canisters, however there have been reports in the past of incompatibility due to the length of the pin on the stove end not being able to depress the valve on the MSR canisters.

All MSR stoves come with their own fuel pump. That being said replacements are available, as are parts and maintenance kits for field repairs.

I have successfully used unleaded (regular, mid, and premium), diesel, and kerosene, along with the standard white gas. works great, just doesn't burn quite as cleanly during startup.

generally speaking the wider apart the bars are, the more stable your roof load will be. that having been said, the measurement should be taken from the inside edges of both bars (back side of the front bar, front side of the back bar)

The number of kayaks you can get on your roof is dictated by the length of your load bars. If you're looking for two sets of Hullavators (one for each side) you'll want a set of at least 58" bars.

A lot of times, back pain can result from incorrect posture as well as the kayaks outfitting. when you're paddling it can be very helpful to keep your feet on the braces and pushing to keep your back against the seat back in order to have a "dinner-table" posture. To answer your question, this seat does have decent support, however posture has a lot to do with back pain as well.

This boat has adjustable foot braces that should be able to adjust far enough for you. However the only true way to know is to try sitting in the boat, or find measurements and match them to your inseam.

This boat falls under the category of "sit-on-top" kayaks. One of the pluses for this style of kayak is that they are very stable, and in the event of a capsize, they are very easy to climb back on top of. The structure of the boat is hollow with few openings into the inner chamber. And to answer your second questions simply, it would be very difficult to sink this boat. However if the front hatch (gray and black rubber piece) is not secured properly, the boat could sink more easily.

It depends on what activity you're doing with it. This jacket is relatively lightweight and is a simple, no frills jacket. It would work well for rafting, whitewater kayaking, sea kayaking, sailing, or just about any other boating you might be interested. This jacket is a unisex jacket so it will fit both men and women well, however women may be more comfortable in a jacket with a little more sculpting like the Kokatat MsFit.

Generally stand up paddling (SUP) utilizes what looks basically like an extended canoe paddle. The Corryvrecken is designed for a low angle kayak stroke and would be very uncomfortable and inefficient for SUPing. Unfortunately it does not look like Backcountry carries SUP paddles. I do know that Werner makes a number of models specifically for SUPing