Briar Pipe bent Kit: Tools and Preparation question(s)

Shoto:
I'm a newbie pipe maker too but I've cobbled together a few cherry woods and a briar from a kit.
Here's my take.
#1 simplify. Were not building heart valves here. They're pipes. God help the guy who got stuck with a heart valve I made.
The nice thing about a kit is the hard stuff is done. By hard I mean the make or break stuff. The drilling is to me what makes a pipe. And the drilling is the stuff that requires some sort of power tools and moderate skill in using them.
You truly can finish a kit with nothing but basic hand tools. Just a case of how long you want to work on it.
Really your doing 2 things.
1) Roughing things out by removing all the "obvious" wood. The stuff that no doubt has to go.
2) Fine tuning by removing the remaining stuff that doesn't look like the pipe you want to make. This includes the fine sanding.
Personally I couldn't live without my belt sander (for pipes and most any other wood project). I use it for all the rough shaping, at least where I can get to. The waist of the bowl/shank will likely need a different approach. I just have a typical hand held belt sander. Put it in the left hand the block in the right and hold on for dear life.
Your carving knife will likely serve you well. I like to use a rasp and files but it's the same basic idea.
I tried a Dremel with a carbide cutting wheel and found it wasn't my cup of tea. I like more control. But Sappo and others use a Dremel.
Also for me the most useful thing I own is 60 grit sand paper. It's amazing how easy and fast you can cut away wood and get your shape with some good old fashioned hand sanding. This suits me best. I like to feel the pipe and ponder things while I sand. If left to my own devices in most things I will hurry and screw up if I try to go too fast.
Either smooth or rustication is relatively easy to do. I did some rustication on mine using a Dremel (guess I lied before. I forgot I used a Dremel for this) with a chucked drywall screw with the head broken off. It chews things up nicely and gives you good control almost like a big pen. You can l;iterally use anythign though for rustication. Whatever will chew up wood.
I bought most of my basic finishing supplies form PIMO. I bought buffing wheel arbors, and 3 different buffs to use in my drill press, along with some tripoli and carnuba. You don't need the buff and arbors and can polish by hand. But it will take longer and probably give you less satisfactory results. Maybe they make little buffs for a dremel. I don't know.
If you choose to stain it, I'd recommend the water based Minwax stain they sell at the big boxes. You can also order die powder from Pimo and mix it your self with denatured alchohol. But for simplicity the Minwax stuff works well. I know Sappo also used it on his recent pipes and they look good.
Short story is just take your time, use common sense and have fun.
Maybe also some of our more advanced pipe making members like pipemaker and rafter will chime in with advice.
Keep us posted.

I am not sure my advice would be particularly helpful since I have the pipemaking bug to the extent that I have tooled up considerably. The only thing I want but don't yet have is a sandblasting cabinet (thousand of dollars for a decent setup). Also, your questions are a little too general to answer really, but here goes:
1) what kind of tools do you have? Power tools? Vices?
lathe, drill press, bandsaw, belt sander, disc sander, hand drills, dremel, files, vices, rasps, sandpaper, etc., etc.
2) Do you have a work bench?
yes
3) What kind of preparation do you go through?
design a pipe that is appropriate for the block you have on hand, draw a rough sketch on the side of the block then, if drilling yourself, carefully layout the tobacco chamber, airway and mortise for drilling.
4) Do you have any MO before, during, after building a pipe? (e.g. not making the walls too thin, let it sit 3-4weeks after smoking?)
Not sure where to start on this one, but I would leave at least 1/4 inch all around for safety.
5) where do yo purchase your tools? stain? wax?
online from lots of different places depending upon what I am looking for.
6) if you were to choose three tools from your shop and were to build a pipe what would they be?
lathe, bandsaw, and belt sander
7) what is the most common mistake?
leaving a chunky transition between shank and bowl; think of it as two separate pieces; also it is very difficult at first to get a well-fitted stem
8) whats an easier finish for beginners? rusticated? smooth?
smooth; I still haven't found my go to rustication technique and all techniques involve a high chance of gouging into a hand or other body part
9) What is the estimate USD (w/all the tools put together) costs in making a good pipe? or is just skill?
At least $40 in materials alone for a decent briar pipe with a handmade stem. Tools you can spend as much as you want.

I have very few tools,

1 A variable speed hand drill

2. about 2 dozen assorted wood files, but I really only use 4- A bastard file very aggressive- a "Double Cut" lines on the file criss- cross med aggressiveness, a finish file, lines are finer and only go one direction and a round fine finish file.

3. A Dremel, this is a great carving tool and has replaced many files.

4. A Pimo drill bit that squares the shank and drills the mortise at the same time

5 assorted drill bits/ including countersinks and Pimo also sales rounded bore bits, that are just a spade drill bit with the point knocked off and the blades rounded to a bowl shape.

6. A Vise, this is probably the best spent money ever.

a crapload of Sandpaper and leather dyes.

7. assorted waxes- and various polishing pads (disc)for the hand drill.

8. a hand saw to cut away excess briar saves a lot of filing.

I like using files, I have used sanding disc to rough out the design but you have to be very careful around the shank area, one slip and your shank is ruined.

9. Also you can use Hole Saws blades in the drill, like the ones plumbers use and they are often used for metal work, they are a long cylinder, hollow in the middle, with cutters at the bottom?? not sure what the official name is, but those can be used to cut the outside bowl to a perfect circle after the bore is drilled and you can use them to cut the shank as well.

I hope that helps, I know my way is kinda primitive, but I'm cheap and not in a hurry.