I never said he had no trouble with Mace. I believe he was trying to kill Mace at first. When Palpy was on the floor trowing the lightning, he wasnt giving it his all. It was more so in defence of being killed to show Anakin that the Jedi were wrong to try to kill him and that gave Ani the chance to think about what Palpy said about saving Padme. If Sids wanted to overwhelm Mace with the lightning at the time, he could have. The reason he didnt was because he knew that Skywalker had conflict in him, thus giving him more time to think about saving his wife.
Palpy made it look as if he was decaying. He wanted Anakin to think "Look at what Mace is doing to me!" "Im old and weak." And in AOTC, Ani didnt get up right after his ass got filled with lightning. He was on the floor knocked out, with Obi fought Dooku. That was a good 3 min. He came to when Dooku was about to kill Obi. Thats when Ani got up my friend.
I dont think Sids was scared of Yoda. I just think he wanted to avoid the fight. In the saber battle sids was doing very well against Yoda. Yoda was clearly on the attack side, and Sids was blocking everything Yoda was giving him. Force wise, they were even.