LaCie Ethernet Disk RAID questions

I am a new user of a LaCie Ethernet RAID system, and need [a lot of]
helpful
hints. I set it up with the default [RAID 5] configuration since I
don't
know any better. First, a little history:

I have a small home LAN with several computers (mine, wife, daughter,
ham
radio room, weather station, etc.) and have been using NAS disks to
share and
store files. I've also been making regular backups to one of the NAS
disks
until a few weeks ago when one failed (a Western Digital My Book).

Normally I would not be concerned about a disk failure because
anything backed
up to a NAS disk is a duplicate of what's on a computer. Any shared
files that
are not duplicated are almost "disposable" files that I'm not
concerned about
losing. ... Until a few weeks ago.

I was doing some computer juggling; replacing the one in my radio room
and using
it to upgrade the one for the wife. I put a extra duplicate of my
files (tax
info, radio logs, accounts, pictures) on the Western Digital drive
but, stupid
me, cleaned up and deleted stuff from the [now] wife's computer before
I copied
everything to the new computer. Since I distilled my files down to a
single
point of failure,... it failed.

Anyway, I spotted a good deal on a LaCie Ethernet Disk RAID storage
system which
arrived last week. Right away I connected it to my LAN, set it up
with its
default configuration (as I mentioned), and put backups from all the
computer
on it. Now I'm reading the manual a bit closer and have questions.

1. The default RAID configuration was RAID 5, but it can also do other
versions.
I have a basic idea of what the different versions are but, in newbee
terms, what
are the benefits/advantages/disadvantages/etc. of RAID 1, RAID 5, RAID
5+ Spare,
or RAID 10 (1+0)? (I know that RAID 0 isn't a good idea.)

2. The system reports firmware of 1.3, build 524. The LaCie web site
shows an
upgrade vesion of 1.3, build 531. Their documentation refers to a 1.4
version.
I haven't been able to find anything detailing the difference in the
various
versions to determine if there is any advantage to updating. Any
comments,
advice or suggestions.

3. The system came with 4, 500GB Samsung disk drives. If one were to
ever need
replacing does it need to be replaced with the exact same manufacturer
and model
drive, or would any brand of SATA2 disk drive of the same capacity
work?

4. I have been using the backup utility that is part of the Windows
version on
any of the computers. Is it any different that the Windows Backup
Software that
LaCie provides on their utility/startup disk?

5. The system proportions space between shared folders and backup
space. During
configuration it asked for how much space to allocate to shared
folders (200 MB
minimum). However, when I ran my backups nothing was written to the
backup
space. The various backup files went into the public folder. So
what's the
difference in the file spaces and what and how are backup files
written to the
allocated backup space? Again, any comments, advice, or suggestions
on how I
should configure and use the different space?

6. When not being actively used, other NAS devices I've used will spin
down and
go into a hibernate or standby mode. Do the disk drives in this LaCie
system
do something similar? Does it help the life of the drives? Just
curious; I
have a Maxtor Shared Storage drive that "hibernates" that's been going
almost
two years (so far).

7. This LaCie system has two ethernet ports. Is there any advantage
to plugging
them both into my switch?

I appreciate any comments. This is new to me and I haven't yet been
to the
bookstore to see if there are any "Dummy" books on the subject.