'The Lucy Show' trivia section

I was browsing through the trivia section when I came across these. I know I have heard stories of Lucille being feisty and difficult to work with, but are all of these really true? Especially the part where Lucy's OWN mother had admitted it herself that Lucy was really bitch? 

Gary Marshall became a staff writer on the show. After he submitted a script to Lucy for her approval, she handed it back a few minutes later with writing in magic marker on the front page:"THIS IS SH[I]T!!!!"

Joan Blondell made an appearance on the show, and Ball told her she "stunk" in between takes. Blondell responded in front of the audience: " F___ you Lucille Ball! "

According to the Lucille Ball biography "Ball of Fire", Dede Ball, Lucy's Mom, and Lucy were at a social event, and they were introduced to a guest. At one point in the conversation Dede warned the guest, "Be careful with Lucy! She's a bitch!". And Lucy replied, " No I'm not! Only when I'm working". To which Dede replied " When else does anybody see you?"