SmallRig Cold Shoe Mount Top Handle

Unfortunately, this handle does not include a start and stop button (please see the official product photos). A handle that does have a start and stop feature would be these products instead: For Sony: https://www.bhphotovideo.com/c/product/1611120-REG/smallrig_htn2670b_nato_top_handle_with.html For Panasonic: https://www.bhphotovideo.com/c/product/1582513-REG/smallrig_2880_nato_top_handle_with.html

That cage has the larger ARRI-Style Mount with Thumbscrew on the top. Because of that SmallRig recommends BH #SM2165B which is the SmallRig ARRI-Style Mount Top Handle. https://bhpho.to/2vAhNYv

Yes, this handle is compatible with the SmallRig 2203 Full Cage for BMPCC 4K. https://bhpho.to/2U2ye73

You can use a: Kondor Blue ARRI-Style Anti Twist Spacer Plate for Mini Quick Release Plate https://www.bhphotovideo.com/c/product/1537907-REG/kondor_blue_kb_arriqr_arri_pin_anti_twist.html or 16x9 Cine Lock Quick Release Mount and ARRI 3/8"-16 Spacer Kit https://www.bhphotovideo.com/c/product/1438604-REG/16x9_cine_lock_quick_release.html

Yes

RED DSMC2 offers 1/4"-20 threading above the camera body for mounting handles like the SmallRig MFR #MD2393.

This will not work with the Ronin-M.

It would not be recommended. This part is designed to work with a cage for a smaller Mirrorless or DSLR camera, not a heavy cinema camera.