I actually prefer this setup. The only downside I can think of is that if you lose a key and want to ensure security, you would need to rekey all of the locks.

We have that situation here and it is great - although there is the downside kymike mentioned. Some brands you can rekey yourself with a special pin - we did this when we replaced our front door handleset.

We have all keyed the same EXCEPT for one (the side door). Only my husband and I have the main key. The exception is the only key that we give out as necessary -- to our kids, the housekeeper, neighbors (in case someone is locked out or we ask a favor of them that requires access, etc.), etc. We can deadbolt the exception from the inside as well, so we can control when that door can be used. This also reduces the chances of us having too many main keys out there, lost, etc.

We did the same thing as Musings. Our exception is the side door into the garage and you would still have to go through the door from the garage into the house, which is keyed with the main key. Might be a bit convoluted! The side door into the garage is also alarmed, so it could not be used unless we program the alarm to bypass the signal for that occasion.

The house also came with a deadbolt on the master bedroom door. The previous owners had many kids hanging out at the house and would lock up their room. We are just approaching the teen years and it seemed like something we might want to use in the future. The main keys (DH and I) will open that door and all other. Secondary keys open everything else, but not master. Tertiary key only opens the side garage door.

Set interior locks all the same. Side doors 1 lock, front 1 lock and back 1 lock. That should be ok.

All ours on our current build are keyed the same. The door to the mud room will have a keyless entry system with dead bolt. That way we don't have to give out any keys and can reprogram the keyless with a new code whenever we need to.

I think your problem could be solved by a keyed/code combination lock on one door. Anyone had actual experience with the code locks by schlage and kwikset? I'm planning to key all my doors the same and put the code deadbolt on my side door; then I won't have to give out a key to anyone.
It even has the ability to have a main family code and a secondary code for service people. Then if you need to change the code, the family code doesn't have to change.

My BFF has the schlage and that's what I'm going with. She has had hers for about 2 years now and no problems.

If you use the SmartKey system (found in Weisers and Kwiksets), the key coding can be changed very easily by the homeowner. It takes under a minute each and that's with reading the instructions.

Here is a link that might be useful: SmartKey

emtek came out recently with a key pad entry that goes with the rest of our knobs. i ordered it a couple of weeks ago, so should be in soon. thanks for all the good advice.

All of our doors are keyed the same and I like it.