Is it true that more than one security protection on a system makes the computer run slower?

I was told that my computer is running reallllly slow at start up and shut down because I am running more than one security protection. If so and I take all but one off, am I more suspetible to viruses, trojens, etc.?

Which internet security is best overall and has free tech support? Which one has a simple user interface?

I want complete internet security protection.(Ex. anti-virus, anti-spyware, email protection, firewall, antiphishing, etc. Also not sure if any have free tech support,but just need to be able to call them and have them help me troubleshoot issues free of charge .

Can banks offering Internet Banking expect their customers to have GREAT Internet security protection?

Can banks offering Internet Banking expect their customers to have better Internet security protection than the banks' own protection? Details and sources please?
Can banks offering Internet Banking expect their customers to have better Internet security protection than the banks' own protection?

In this scenario the customer's username n password were stolen via a keylogger following which the perpetrator steals the customer's money. (How does this make a difference?) Can the bank insist that the customer's security be better than its own? (I'm on the customer's side)

Details and sources please?