Few question about LVM and Luks

1.Did i need to put LVM partition to /etc/fstab to survive reboot?

1. I have: 3 partition

-primary partition (sdb1)(1BG) where i made LVM (pv-sdb1,vg-sdb1,lv-sdb1)

-extended partition(sdb2) on same disc with rest of disk space (9GB)

-logic partition (sdb5) with 1GB space. At the begining i add 500M to VG of first patition

Now i want to again 100M to same VG and again but rest of the space of this partition

What i must to do?!

1. every time i make encryption of partitions, ask for password to one partition (for example nr.4) but after reboot ask for password for another. It is possible to ask for password in same time for all partitions (password is not the same)