Life interest, land registry and lasting power of attorney

Mother and Father made wills appointing 3 execs/trustees (each other, son and one other). Will left deceased’s half share to life interest trust (to allow surviving spouse to continue to live in the property following first death). Father passed. Land is currently registered in names of Mother and Father subject to a Form A restriction. Does land now need to be registered in names of Mother and the two other ts of the Father? Are there any potential problems if left in the sole name of the Mother (subject to the Form A restriction) e.g. problems with local authorities if care was required? Or could this be arranged at the relevant time if necessary?
Do both of the other ts need to be named on the title, ie son and the other? Or could it just be in names of Mother and son? This is preferable.
Mother is also wishing to make a property LPA. She wishes to appoint son as sole attorney (with others individuals as replacements). If property needed to be sold and Mother lacked capacity, could this create problems if son was the only other trustee named on the title to the property and he was also the sole attorney? Should there be two attorneys on the LPA and would this overcome any potential issues if house needs to be sold?
Your comments would be most welcome.