Stuffing Box temperature

It shouldn't get hot to the touch, if hot enough it can ruin the shaft, you should be able to get a good seal and the fitting stays at ambient temperature. You may have it tighter than it need be. If it is dry at rest, it still may drip a few drops a minute when the shaft is turning, which is fine. Stefan's suggestion is a good one; however,  all you really need to do is repack the stuffing box. Last time round I used teflon dripless packing, playdough like stuff held between rings of traditional flax packing. Great stuff, no drips whatsoever at rest or in use.

Yes, you can repack a stuffing box while the boat is still in the water. However, you need to figure it all out before you give it a go because when you remove the packing nut, it will let a steady flow of water into the boat. How much water is dictated by the particular stuffing box, but in any case it's not something you can leave overnight and pick up again the morning....or at least I don't recommend it!!

If you've tightened it as you mention, you've already figured out how it works. Tightening the packing nut pushes in on rings of flax packing, compressing them and therefore providing a seal against the shaft. The more compression, the tighter the seal, but also the greater the friction, as you've found.

There are 2 basic designs I've seen. When you remove the packing nut in one, you reveal a compression spacer, when removed, this exposes the flax packing in a tube around the shaft. The second is very similar, but more simple - when you remove the packing nut, there is no compression spacer, the flax packing goes into the packing nut, and you simply tighten this against the face of the stuffing box.

There should also ALWAYS be a locknut astern of the packing nut. Be sure this is always doing its job, as the shaft can spin the packing nut off the stuffing box, which is of course not a good thing.

You need to buy the right size flax - generally dictated by your shaft size, but buy a size bigger and a size smaller than you need if you're doing this in the water as you probably don't want to run off to the store when you discover you've got the wrong size. I also strongly recommend "drip-free packing", you'll find it at most marine stores, but you still need the traditional flax packing to use in conjunction with this - get teflon impregnated flax.

The hardest part, (after getting the packing nut loose in most cases, but it sounds like this is not a problem in your case), is getting the old packing out. Get the tool for this, which looks like a miniature corkscrew - this helps you dig the old packing out.

There are probably a million different books on boat maintenance, but I highly recommend any boat owner to buy Nigel Calder's "Boatowner's Mechanical and Electrical Manual." GREAT book and covers pretty much anything that comes up.

The dripless, or PSS shaft seals are a great new innovation, and they are used with great success on many, many boats. However, 2 caveats - they do have the potential for catastrophic failure, whereas a traditional stuffing box does not, (unless the lock nut as per the above is not doing its thing); secondly, they are a mechanical seal maintained by a rotating collar pressing, (via spring pressure), against a fixed flange - keeping the seal requires that the two surfaces stay mated and flush all the time, so engines with excessive vibration may have issues. As many Contessas have 1 cylinder engines, which typically jump around quite a lot, they may not be the best candidate for a PSS shaft seal. Probably can be done just fine by increasing the spring pressure, but something to consider.

Good luck.