My dog(s) poop and pee in the house and are sometimes destructive when I am gone

Question
I have 6 dogs total; one of which is a full blooded Weimaraner, 3 are puppies of the Weimar that are mixed w/ a lab mix and then we have 2 mutts. My 2 mutts were my first dogs into the pack and have never been any kind of trouble.  My Weimar joined the pack when she was 2 (we have now had her 2 years) and has always had a problem with pooping and peeing in the house when we are not home. She occasionally will chew things up; however, she usually does not chew up anything that would normally have my (or my husbands) scent on it and she doesn't show any normal signs of seperation anxiety such as whining and barking as we leave, etc. Most of the time she does not chew but 99% of the time my husband and I come home she has pooped and peed in the same area as before. We clean it as much as we can to get the smell out but you can only do so much when it becomes an every day occurrence...
Her 3 puppies that we kept are usually crated while we are gone because they also like to chew on things. One of the puppies, a female, likes to actually chew our walls down into the dry wall!!! I have had many holes that I have had to replaster because she decided to eat my walls...hence the reason why we must crate her. The "puppies" are a year and a half old now and are plenty old enough to be out and about in the house but we cannot seem to get their mother well behaved enough to allow all of them to be out.
The "puppies" do show signs of separation anxiety and bark and whine constantly when we leave and when we come home. They will even bark like crazy if I run out to my car for a second and come right back inside. It doesn't matter how long I have been outside. They still bark.
As far as exercise goes, I have to admit that I cannot walk/run them much because I live in an area that doesn't have sidewalks and is quite dangerous to walk them. Plus, I do not have an off leash dog park to utilize either, nor the time to drive to the closest park to walk them. So, most of the time we utilize our large yard and play ball/Frisbee.
Please help me with these issues. I really need help...thanks!


Answer
You may not like my answer, but I think you have way too many untrained dogs, and are expecting too much of them.  It's hard enough to train one Weimaraner that is un-house trained at age 2, but then to have kept the puppies on top of that must have been really overwhelming.  It's clear that you have not been able to give them sufficient exercise and training to prevent them from also becoming destructive.  This is probably one of the most needy breeds when it comes to physical exercise - these dogs sound bored and anxious, probably due to their not getting enough mental exercise (from training) and physical exercise.  The first thing I would do is to go back to house training 101 with your female - read "Way to Go - How to House Train a Dog of Any Age" by Patricia McConnell.  You have to find a way to give this dog sufficient activity, but still confine her when you cannot supervise her.  If you continue to allow her to have freedom in your house, she will continue to use it as a toilet, because she simply does not understand where the toilet really is - outdoors.  Make sure that you don't scold her for accidents - that will make it less likely that she will want to "go" in front of you when you have her out on the leash.  When she does go in the right spot, praise her, and even offer a treat once in a while when she finishes.
One other thing you can try is to enroll the dogs in obedience class (clicker training is great because it gets the dog thinking!) and then after that, you may want to try agility or rally obedience - or even field training.  If you can't devote enough time to the dogs, think about finding homes for the pups where they will be able to get more individual attention, and thus more exercise.  
Another thing to try with regard to the chewing problem is to use a Buster Cube or other interactive toy to feed the dogs their meals from - it gives them mental stimulation as they try to get the kibbles out (also make sure the food is very high quality so they aren't chewing to seek nutrition they aren't getting).  Generally, dogs chew because it feels good, soothes anxiety, or occupies their time, not because they are being mischievous.  If you scold them after the fact, they get more anxious (even though they don't have a clue what you were mad about) and will chew more to assuage the anxiety.  
Simple rule for household destruction and soiling: supervise the dog(s)at all times.  When you can't supervise directly, crate them or contain them.  Exercise till they are tired.  (A tired dog is a good dog.) And, train the dogs!  There's really no substitute for being able to say "leave it" and the dog does:-))  If you need help with lessons, go to www.clickerlessons.com.