A couple of form questions

Hello FB. Was looking to get advice on form.

I feel like I'm not really doing anything while moving during side hip raises. I keep tight and I keep off the floor(I have to keep my knees bent because I'm still a heavy guy). I really just feel like I'm holding my self up on my elbow shoulder and knees. It just ends up burning my shoulder up more than anything else.

Another one is toe taps. I only get a burn in my upper thighs and not my abs at all.

And finally, any thing I do on my stomach for my back(ex back bow) is painful for me. I have that extra cartilage at the bottom of my strenum that sticks out pretty far(if you don't know what that is it's like having an extra quarter inch of bone sticking out right above your abs)...is there another form I can use to do these? I've tried using extra padding but by the time I have enough to where it doesn't hurt or feel uncomfortable the pads are taking all the work out of it.

Thanks in advance FB!