At this point I would only remove what you KNOW is bad: the honeysuckle, multiflora rose, any ligustrums, etc. Try to identify the rest (you may have to wait for it to leaf out again) before you remove what you don't know. There could be some good things there (native shrubs). Garden Web has an excellent "Name that Plant" forum. You can post pictures there and get help identifying stuff. Although for best results, post your pictures on a web hosting site like photobucket.com so that you don't have to reduce them. Then provide a link to your pictures. I certainly would not plant grass back in place of what you clear out. That seems very unnatural for a woods setting. Plus, then you have the maintenance of mowing it and the potential damage to trees as you mow around them. My in-laws did that and now spend a lot of time and money mowing it and having other people mow it. Just add mulch (leaves, wood chips, even some grass clippings) back to the area to allow it to be a wooded setting. I lay old logs throughout my woods to create informal paths for the kids. Some native plants buried under all that invasive stuff will return, and you can add more. Ferns, spring wildflowers, native shrubs are all appropriate for the area. Good luck. I would certainly put my first efforts into getting rid of any invasive plants that have berries on them so that you can prevent the spread of new plants. Put those berries in the TRASH. Then go for the ones without berries (but which are still invasive).

Olympic Rescue it is the best I have used. I like the smoother finish and it looks much better than the rough garbage that Behr Deck-Over of Rust-Oleum has to offer. The main thing with using Olympic Rescue it is to get the deck clean and dry. The paint that will not come off with a pressure washer is actually the only good paint you have on your deck and it does not have to be removed. Why do I say that it is the only good paint. It is paint that has bonded to the wood like it all should have done if it was super great paint as advertised...lol

Having just now looked at your second set of pictures I'm going to reconsider one thing, correct another, and add yet another comment or two. Reconsidering, I think it's very possible that the primary wood is Walnut. The grain on your drawer front could easily have been plainsawn from a crotch or a shoulder of a native Black Walnut tree the size of which were being cut during the last half of the 19th century. They don't come that size any more for commercial cutters. Correcting, it is obviously the quarter-turn piece of trim that you are missing, not a piece of the straight run as I wrote. No excuse for my mistake. Lazy_gardens got it right and correctly described the machine tool procedure for replicating the missing piece. It's maybe a little more complicated than you might think if you're not a woodworker, but it's pretty straightforward procedure if you are. Since you had a nice closeup photo of the drawerfront I'll say a bit more about the wood. The trim moulding is of pieces like this is usually quartersawn Walnut. I've enlarged this view quite a bit, and I assume if you click on it you'll see it as I do. In the enlargement, which is rather fuzzy, you'll see small lines which may actually be there or may simply be a result of the enlargement process... so get out your magnifying glass and look at that part of the drawer front where the finish is pretty much worn off (I circled in red one such area). If you see an alternating pattern of long and short straight lines, parallel to each other, the larger not much longer than 1/4 inch, the shorter closer to 1/8 inch, then you're looking at quarter-sawn Walnut. You are not looking at the "grain" of the wood, you're looking at pores. If you don't see the pattern then you're probably not looking at Walnut, at least not quarter-sawn Walnut; maybe Cherry, maybe Poplar, but not quarter-sawn Walnut. You can try looking at the drawer front itself, but that piece of wood was far more likely plain-sawn (also called falt-sawn), so what you'll be seeing is the grain, not the pores, making a certain identification more problematic. The other comment was about your link to Shellac finishing. That had more good info than any piece on shellac finishing I've ever seen on the web. The only fault I find is that he should have told you that the brush you want is one of those "white-haired, single-use, bare-wood-handled" brushes that are the cheapest brushes you can find at the hardware store or home center. Nothing else is better for applying shellac. And if you want to use it more than once, you don't need to use straight ammonia, just mix a splash of ammonia with enough water to dip the brush into. When it makes contact with the shellac it will almost instantly turn purple, rub it in your palm (yes, you can use a glove if you must), rinse it, and then wash it with hand soap and tepid water. The bristles will no longer be white, but when dry, the brush will be ready to use again. Needless to say, they're so cheap you can afford more than one.

I'm guessing the concern or regulation isn't about conservation - it's the danger that your house will catch on fire when a spark from a wildfire lands on the siding. I agree with Klem that there's no sense in discarding redwood. If there's a way to keep redwood on the exterior, then doing so really depends on how risk-averse you are, knowing whatever fuels are in your area (i.e., the age and the structure of the forest within a few miles and in the immediate vicinity). If allowed by local code, I personally would be tempted to keep the redwood siding and simultaneously take other fire-wise measures such as removing trees within 100' or so of the house and installing a sprinkler system that can function in a power outage. (If these suggestions don't make sense, google "firewise".) If the regulations say you absolutely cannot keep the siding without gypsum board underneath, sounds like you need to cover or lose the redwood. Again, there actually is a good reason for that in fire-prone areas.