Guitar (ist) gear question: pedal power?

I have always used 9v batteries with pedals except for those without the option because when I was playing in bands, I didn't have pedals. I never needed a pedal board and just used a couple of pedals as I wanted to, when I wanted to. Now I am thinking about going to some sort of pedal power and in fact several years ago I bought some sort of pedal power unit (not Powertrain) with IIRC a wall wart and connectors for some pedals.
All my pedals say 9v but some say 150mv, some 800mv one 1300mv, but most just say 9v. Boss pedals say to only use a certain Boss power adapter, I'm sure different ones will work though.. So.. my question: Does it matter if I power a 800mv pedal with a 1000mv (1v) or 1.3v adapter AND what about using AC power and a transformer to power pedals. How does it know the pedal requirements and what if I'm sending 1.5v to a pedal that has a 15mv requirement? Is there anything I should know? Anything I shouldn't do if I have an adapter that is close but different, like the pedal that requires 800mv, the closest I have is 1v... then what about the older pedals that just say 9v?
I'm thinking of building a board and want to know.. I don't even know the questions to ask other than those I asked, but if I build a board or maybe a couple with two power supplies, are there things (power things) that I need to know?
Also. Most of my pedals are some sort of boost, OD, or Distortion and I usually run them into the input. I've never really understood the FX loop because of mostly just using pedals to goose the input. I've always sort of thought that Boost/OD/Dist pedals should go in front of the input and modulation type pedals maybe into the loop BUT last week I got an EHX MEL9 and it says that is should be used in the input, not the loop. So what are your thoughts on the order of pedals? Say I'm using a Boost, a Fuzz, Distortion, something like a Callista (tremolo/chorus), a MEL9, and a Wah? Is there a right or wrong order and are there some that should be in an FX loop instead of into the input?
 
Two questions there I guess, probably more since I don't even know what it is that I don't know.
 
Thanks for any help.
Julien

I pretty much only ever use 2 or 3 BOSS pedals.
The first pedal in the line is their TU tuner, which doubles as a power supply, accommodating up to 6 (i think) other pedals.  Assuming they're either BOSS or similar power-pullers, i'd look into getting their tuner.  It's a tuner, a power supply, and a great on/off switch for the instrument.  This keeps me down to one  wall-wart.  
 
I don't know if that tuner would power other pedals with a battery.  I've never tried it, but if it works you'd have a plug-free line of pedals that hopefully wouldn't drain a battery in one set.

Need a brick!
Two pedals coming from Catalinbread. I was going to just order a Dirty Little Secret but they have a special with the purchase of a pedal you can get a Super Chili Picoso boost pedal for $39.99
The DLS emulates an early Marshall. Internal presence pot and internal switch to choose between the Super Bass and SLP voicing. NICE!
http://catalinbread.com/product-category/pedals/
I may try to build my own board from wood, unless I can find a cheap used one. I like the Holeyboard but don't want to spend that much.
Thanks all..
J

Try the black or white industrial grade velcro. The glue is much better than the ordinary stuff. I put four small pieces of the hook side on the pedals then use cheap carpet tiles to cover a board. The velcro sticks to the carpet very well indeed.