As a bass player who never wanted to be anything else I think he has some valid arguments. I personally hate the guitarist who plays bass because they play like a guitarist. That being said I have been in a project as a bass player with a guitarist also on bass and we made some good sounds, mainly because I played bass lines and held it all together while he played bass like a guitarist.
Totally agree with the practice and knowing the arrangements before hitting the studio especially if your paying for the time. Bit different just writing and arranging in your own studio.
As for new strings, that is a personal preference and really depends on what style you are trying for. I hate new strings unless I am trying for that punk twang or want a more mid range to fit in with bottom heavy metal guitars. Mind you that being said strings do have a life span and will sound shit and wont hold a tune after a certain amount of time and becomes pretty obvious when they have had their day. Good thing is bass strings are cheaper now that they were 15 years ago and easier to get the brand and size I like. Haven't resorted to boiling a set in years