Help Needed for wall thimble installation

I am finally ready to install my englander stove in my basement. I purchased the 3" simpson dura vent kit. I would like to come off the tee and run the 3" pipe straight up through my basement ceiling which is sheetrocked. Once I have the pipe over the ceiling and positoned between the the first floor floor joist I would place a 90 deree bend an thenrun the pipe out over my sill plate through my sheeting. My question is where should I install the wall thimble. I have seen some pictures of the installation and the wall thimble is postioned at the eexterior wall which makes sense but do I need an additional thimble in postion where the 3" pipe goes through the ceiling?

Can I install the thimble as followed also? Where the 3" pipe goes through the basement ceiling, I can place the interior black side of the thimble flush with the ceiling then install a 90 degree bend then my required horizontal length of pipe to vent out to the side of my house. On the exterior of the house I would place the second half of the thimble in place?

Is the outside air kit really necessary? I have read in the MA code book that outside air is not required if the total volume of space in cubic feet(where the unit is being installed) is equal the the btu output of the unit.

LAstly is there a problem in placing two bend in the exhaust lines to offset the stove so that I can place it in my space symetrically?

Thanks for the fast replythis site is the best. How about this as an alternative solution, do you think I could get away with framing the area between the floor joist with sheetrock that way the pipe is in open space with the rest of the room and not enclosed. To further protect the area between the floor joist I could get some sheet metel and cover the sheetrock in the space with it? I have more than enough space where I would have at all times more than 5" of clearance around the flue at all times just like the wall thimble.

Where the flue penatrates through the ceiling, could I get away with installing a metal grate with square openings in it that way it would still make the space open but at the same time I have a more attractive ceiling.