I don't think it would be a good idea to have Darth Sidious actualy physicaly fight as well. But would force lightning be enough to stop a fully trained jedi?
In RotJ as I remember it Luke threw away his light saber and was tired from his battle with vader. Also it took a number of blasts from the emperor to fully demobilise him.
I think that Darth Sidious posses different powers that prehaps have not been seen yet? Prehaps the Dark side of the force allows its followers more power than the good side. This could help to explain how Maul and Sidious are able to prevent themselves from being detected. If Palpatine is Sidious then he must be one of the most powerful force users ever as he is able to prevent himself from being detected during the funeral of QGJ whilst being surrounded by members of the JC. Remember he was with them on the shuutle as well, whilst on the journey to Naboo.