I am relocating WM to basement wall 10 ft away from parallel, under-slab drain line from an upstairs bathroom. The wall is cinder block and above it is the living room thus no wall space to run vent stack up to the roof. I have following questions:

1- to vent the WM can I perforate the basement wall and run 2" pvc pipe a few feet above grade on the outside, or do all vents have to exit the house up on the roof? If the latter, what solution is there for venting since WM would be too far and too many joists away from nearest vent pipe one floor above?

2- when tying the WM's 2" drain line to under-slab drain line, can I use a "T" tie (90 degree tie) or do I need to use Wye tie and 45 bend?

3 - can I tie the drain for the laundry tub to the WM drain stack and avoid separate drain and vent for the laundry tub?

4- do I put the trap for the WM stack above or under the slab?

Thanks very much for help.

1- to vent the WM can I perforate the basement wall and run 2" pvc pipe a few feet above grade on the outside, or do all vents have to exit the house up on the roof? Yes you may, with restrictions. You may not terminate the vent directly beneath any door, window, building overhang or any ventilation opening of this or any other building, nor shall any such vent terminal be within 10 feet horizontally of such a opening unless it's at least 2 feet above such a opening.
When approved by the Inspector the vent terminal shall be located at least 10 feet horizontally from any lot line. It shall also be turned up and screened.
(Chapter#14, Sections 1404 .4 and .5 of the Standard plumbing Code)

2- when tying the WM's 2" drain line to under-slab drain line, can I use a "T" tie (90 degree tie) or do I need to use Wye tie and 45 bend? You may not use a sanitary tee on its side under the slab. Go with the combo.

3 - can I tie the drain for the laundry tub to the WM drain stack and avoid separate drain and vent for the laundry tub?
Not too good a idea. Your standpipe tee to pick up the laundry tray would be a little less the half way up the washer stand pipe. If the discharge built up in the washer stand pipe where do do you think it will drain to. Check with your local code to make sure but I would tie the sink to WM vent if code allowed a wet vent on the WM.

4- do I put the trap for the WM stack above or under the slab? Above the floor.
We come off the vent as close to the floor as possible and run our standpipes at least 36 inches high.