I'm also using the UWW. Pretty good lubricity. The gold class shampoo is also good.. some prefer that over UWW.

1. Mine's been over a year for 1 bar. Break it up to 3-4 pieces.. don't use the whole bar at once.
2. Yes.. try that first. No idea as i've not used. I use the permaglass clay.. its around the same price point.. works fine.
3. No. Compound and polish are to be worked with when wet.. not left to dry. Only for wax/equivalent is curing recommended.
4. Yes for compound and polish. Wax/equivalent.. do the whole car.
5. Yes, paste/liquid is much more durable than spray. Spray is much faster.. so its a trade off. If you combine both, ie. wax monthly and spray weekly it is much easier to maintain. I rarely need to clay following this routine and when i do it doesn't take much time. To each their own i guess.

Do get lots of soft microfiber cloths.

On compound and polish, you start with a dry surface. Work your polish or compound with a sponge pad (give it a bit of elbow grease), but not until dry! Just give it a 15 second rub, then buff off and INSPECT. If the oxidation or scratch is still visible, repeat, if ok move to the next section. Allowing it to dry will be a pain to remove! Always buff off immediately.

Polish after compound is optional if your compound left some hazing (esp on dark cars, else I skip)

No need to wash if you're using wax or oil based sealants. Need to wash and/or alcohol wipe if you are planning to coat with hard coating.

I don't know that pad but should be ok, just don't use the same pad without cleaning it first.

Hope it helps

Ouch, did I just read that you compounded the whole car by hand? 10 for effort but say bye bye to your arms 
If you're planning to compound the whole car, we recommend a proper DA Polisher. It covers a wider surface area!
The Meguiars DA Power Tool only covers a very small surface which would also take time for the whole car.

Still, the DA Power Tool is a great tool to get you started. My suggestion? try panel by panel first!
Work on the panel which needed most attention (they're typically bonnet/trunk due to hairline scratches or stone chips).
Then on days you plan on washing, work on the next panel.

If you really want to do everything in one go, use the DA Polisher (Rupes or equivalent 21mm throw DA polishers).

I remember starting waxing for the first time too. Applied too much and still had residue on the car.
A trick the kind sirs from this forum advised is when you squeeze the sponge and notice the wax oozing out, you've applied too much! 

Anyhow, the idea is practice practice practice You'll be flying through your car in no time.
Nothing beats the satisfaction when its done right

Edit:-
Check out Meguiars QuikTips subforum! Great place to look out for tips and tricks! 

Your first claying will take time.. subsequent should be fast if you maintain it regularly as its just by need. Just don't wait for too much gunk to embed.. else its the same effort again.
You can try using a small piece of microfiber cloth to aid your grip if it keeps dropping

You don't have to let the foam pad dry. Just wring the water out after rinse and you can just continue with the cleaned damp pad.

If the task takes too long, what i would do is to split it over 2 or 3 weekends, ie. 1 weekend do the horizontal panels, the next week vertical, then undercarriage related.. or however else works for you.
On the bright side.. you're getting a good workout..

Nothing beats a proper DA though as other mentioned. I don't own one so can't comment.

It should dry within 10mins in our hot malaysia weather. Do a swipe test with your finger. Normally i apply the whole car with wax.. by then the first panel is ready for buffing.
Don't wait overnight unless you have a closed garage. Dust will settle and you'll be grinding that into the paint when you wipe off.

Apply only a very thin layer for the UPW.. follow the instructions on the package . You can barely see the wax when applied. More is not better.. just wasting product and hard to buff off.