I have no experience with meshless methods, but I will try to answer/comment on your questions.

1. In AceFEM assembling of global matrices and vectors is parallelized. This is certainly true for "Tangent and residual" subroutine and probably also for "Tasks" subroutine. Solving the linear system is also parallelized (Intel MKL PARDISO). I think the only operation not parallelized yet is contact search procedure.

2. I don't know. Virtual element method (VEM) has been implemented in AceGen/AceFEM and it seems many (up to 100) nodes per element are possible. See Aldakheel et. al., 2018 for example.

3. If this helps, Schmied et. al, 2013 have implemented element assembly subroutines in AceGen and used them in LS-Dyna software with explicit time integration.

4. This really depends what you would like to visualize. I would perform visualization out of Mathematica only if there was really no other option. For that purpose you can always save a limited subset of results in some efficient common data format. Maybe something like HDF? As always, I would recommend to start with small example and deal with problems of large example when/if it happens.

I have no experience with meshless methods, but I will try to answer/comment on your questions.

1. In AceFEM assembling of global matrices and vectors ("Tangent and residual" subroutine) is parallelized. Solving the linear system is also parallelized (Intel MKL PARDISO). "Tasks" subroutine is not parallelized, but in general such procedures should not be computationally too intensive.

2. Virtual element method (VEM) has been implemented in AceGen/AceFEM and it seems many (up to 100) nodes per element are possible. See Aldakheel et. al., 2018 for example. See even better explanation in BHudobivnik answer.

3. According to comment by prof. Korelc, explicit simulations are possible. If this helps, Schmied et. al, 2013 have implemented element assembly subroutines in AceGen and used them in LS-Dyna software with explicit time integration.

4. This really depends what you would like to visualize. I would perform visualization out of Mathematica only if there was really no other option. For that purpose you can always save a limited subset of results in some efficient common data format. Maybe something like HDF? As always, I would recommend to start with small example and deal with problems of large example when/if it happens.

I have no experience with meshless methods, but I will try to answer/comment on your questions.

1. In AceFEM assembling of global matrices and vectors is parallelized. This is certainly true for "Tangent and residual" subroutine and probably also for "Tasks" subroutine. Solving the linear system is also parallelized (Intel MKL PARDISO). I think the only operation not parallelized yet is contact search procedure.

2. I don't know. Virtual element method (VEM) has been implemented in AceGen/AceFEM and it seems many (up to 100) nodes per element are possible. See Aldakheel et. al., 2018 for example.

3. If this helps, Schmied et. al, 2013 have implemented element assembly subroutines in AceGen and used them in LS-Dyna software with explicit time integration.

4. This really depends what you would like to visualize. You can always save a limited subset of results in some efficient common data format. Maybe something like HDF? As always, I would reccomend to start with small example and deal with problems of large example when/if it happens.

I have no experience with meshless methods, but I will try to answer/comment on your questions.

1. In AceFEM assembling of global matrices and vectors is parallelized. This is certainly true for "Tangent and residual" subroutine and probably also for "Tasks" subroutine. Solving the linear system is also parallelized (Intel MKL PARDISO). I think the only operation not parallelized yet is contact search procedure.

2. I don't know. Virtual element method (VEM) has been implemented in AceGen/AceFEM and it seems many (up to 100) nodes per element are possible. See Aldakheel et. al., 2018 for example.

3. If this helps, Schmied et. al, 2013 have implemented element assembly subroutines in AceGen and used them in LS-Dyna software with explicit time integration.

4. This really depends what you would like to visualize. I would perform visualization out of Mathematica only if there was really no other option. For that purpose you can always save a limited subset of results in some efficient common data format. Maybe something like HDF? As always, I would recommend to start with small example and deal with problems of large example when/if it happens.