I read your question and I understand your concern.
Your father seems to have undergone all the treatment alternatives for anaplastic meningeoma. Since his brain has undergone some degree of impairment both from meningeoma as well as procedural complications it is to be expected to have some degree of neurological deficit. Some improvement is expected though it can't be exactly predicted how much (especially since I don't know the extent of damage to the brain on imaging), but it takes time and
physiotherapy, takes several months so you have to be patient.
Also seizures are a common complications of
brain tumor, especially meningeoma. The drugs he's taking are widely used and efficient drugs, of course they lower the risk of seizure do not completely remove it, time will tell whether he will have more seizures and treatment must be changed, or if he is seizure free for a long time going to one drug might be possible.
As for tests to be done, they are not necessary rightaway, but periodic imaging will be needed in the future to check for meningeoma recurrence.
Also in evaluating
epilepsy therapy changes in the future, EEG evaluation for epileptiform activity might help decision making on therapy.
I hope to have been of help.