I'm so glad you didn't ever get your kitties declawed.
It is not a simple or painless procedure, and there is the risk of all kinds of other problems as a result, so it was a good decision, despite your current worries.
It seems you've got a little time to work on this - and it will take some time as they weren't trained to not scratch on furniture or rugs to begin with.
Normally I'd recommend Soft Paws - but as you've got a skittish kitty that won't tolerate it, I'm not sure that's the way to go. PLEASE go to the Care & Grooming forum and search on Soft Paws and read up on it - see if there's any way you could make them work.
If not... here's what we did.
1. Cover legs, sides, and backs of furniture with aluminum foil. Use blue tape (painters tape - leaves no residue behind) to hold it in place.
2. Get a lot of throw blankets. Cover your furniture in throw blankets. Will BF be OK with his furniture being draped in throw blankets - to protect it? They are easy to fold up when company's coming over - good friends should understand - and if you want to sit on the furniture without them, they're still easy to fold up and stick somewhere. We covered backs, seats, and arms of cushy recliners and couches with throws. (I'm severely allergic to cats, so that's another reason we did it. We wash and rotate them weekly. It also makes it REALLY convenient, because the cat hair collects on the blankets, not on the furniture, so we never had to worry about vacuuming the furniture - really quite convenient).
3. Purchase Feliway. Feliway is a synthetic hormone that mimics the "friendly" markers in cats' cheeks. It was designed to help inappropriate elimination - but it helps with inappropriate scratching. Pee, poop, and paws all are scents/have scent glands that are "territory" markers. Cheeks and the head have glands that are kind of like "I like this" scents. It doesn't always work - but when you spray Feliway where cats should NOT scratch, it's leaving the wrong scent associated with scratching, and helps (usually) to deter it. Combined with surfaces that are no fun to scratch (aluminum foil), this often does the trick. We had to leave the aluminum foil (replacing it ocassionally) on for about two months - but it worked.
Our kitties didn't like scratching on the throws - we used very open looped knit kind of throws - they were no fun to scratch.
Also, try purchasing some cheap mats - like the kind used on the floors of cars (no plastic on the back though) to toss around on the rugs. Cats are attracted to stuff like that like frogs to Lily pads, and hopefully they'll scratch on them rather than the rugs/carpets themselves.
Have you tried all different kinds of scratchers? Both vertical and horizontal? All different kinds of materials? You know those hard foam "puzzle piece" things they sell at like Target and WalMart - designed for kids play rooms? Our kitties LOVE those. They also like the sloped cardboard scrathers - half-way between horizontal and vertical. Do you have a turbo scratcher? Many cats LOVE these things - both to scratch on and play with.
The other key to scratching is placement. Cats LOVE to scratch and stretch when they wake up and where they play. We have lots of cat trees - and they mostly scratch on these - because they love to sleep and play on them. Almost all of our kitties seem to need a good scratch right before they play, and right after they wake up. So having something they like to scratch on in those places is really helpful to deterring the scratching on the furniture. Of course - they love to sleep on the back of the couch or whatever - so having something right there to scratch is usually important.
Cats learn best by positive reinforcement, so as you work with them to retrain them in their scratching behaviors, rather than focusing on the "no," focus on the "yes," so to speak. When you see one of them scratching on furniture - say "no" by giving them a short, sharp puff of air in the face and say "no" firmly - but make sure you've got a scratching pad/post/mat/whatever nearby - and redirect the cat there - show them you want to scratch there - and even if you do it by moving their paw on it, totally fawn all over them and tell them WHAT good kitties they are.
Any time you see them using an appropriate scratching place, TOTALLY praise them to high heaven. Consider giving them some treats - especially if they're food motivated. Redirection and positive reinforcement are your absolute best friends in this process. And making places they like to scratch no fun to scratch is important.
For instance, if they go ahead and scratch through the aluminum foil - try something else. Get double-sided tape, tape it to large sheets of paper (completely covering it), and tape that up with the blue tape instead of the aluminum foil.
Now - as to the nail clipping. This can be done - even with skittish kitties - if you can pet her. The trick is to get her used to it properly. If you can pet her, when she's sleeping, touch one of her front paws, as you would when you have to clip one. Immediatey let it go. Do this as often as you possibly can for a couple of days or weeks. Let her get used to the idea that you touch her paws and nothing happens. Then progress to pushing one of her nails out. Again - do this as often as you can. When she doesn't feak out - have the clippers ready. Clip ONE CLAW. That's it. We clipped one claw on all of our kitties every day, rotating toes. By the time we got done with the front paws - it was time to start over again. Oh - we kept treats ready. When they woke up when we clipped the claw, we immediately put down a treat. One of our kitties was about two years before we could just put him on our lap and clip all his claws (treat being given inbetween each claw clip) without him freaking. But if you can get one a day, just do it every day.
I'm sure others will have ideas. This is how we managed it (only Feliway didn't exist when we started, but it may help).