I'm looking to replace my heater hoses and I just had some quesitons

1. I can only find one of the heater hoses, which is the one that comes off the nead next to the upper radiator hose. Is the second heater hose the one that comes off the same thing that the lower radiator hose comes off of?

2. There are these short sections (3-5 inches) of hose that run from the firewall to the heater switches, anybody know of an easy way to replace these or do I even need to replace them?

And if anybody asks, I'm doing this for preventive maintainance as I have 100k and I've already busted two hoses so far.