Taxidermy.Net Forum - New to the sport. A few random questions.

This forum is very informative and i wish i would have found it sooner! I mounted my first duck 2 years ago. It was a Wigeon hen and it turned out alright. The neck was a little long and i didnt fan out the tail feathers but i couldnt complain. I will attach photo later. I then mounted a scaup and it was terrible. I sent a blue winged teal and a green winged teal to the taxidermist today and seeing all of those birds made me want to try my luck on another one. I have a redhead that i have been saving to get mounted for about 2.5 years now but just dont have the money to get 3 birds done right now. I got a local taxidermist to sell me a kit with the beak already painted because i didnt have an airbrush. Now to the random questions i mentioned in the topic title....

1. How long will my skin last once detached from the carcass? I'm thinking about skinning it tomorrow, cleaning it the next, and possibly stuffing it 2 or three days after. Is there a way to keep the skin from drying out in between all of these steps?

2. How long do feet last in a non airtight bag? They look pretty dried out. Can you fix this?

3. What is Master's Blend and where can i buy it in quantities adequate for one duck?

4. I see a lot of mounts with a rod coming out of the head. This looks like it would aid in shaping the neck. Is this true? Also, what happens to the wire? is it pulled out or cut off?

5. I dont have a tumbler and i dont know what to use in one. If i were to get some saw dust and a 5 gallon bucket and roll it up and down my driveway for 10 min would that suffice?

6. Do people inject caulk in the head of the mount on top of the artificial skull? Are you able to shape it while it is still wet?

I understand that i have asked a lot of "newbie" questions and i dont expect all of them to be answered. Its kinda just a starting point for me and im sure i will have more.