It’s frustrating, but remember that chewing is a natural, necessary behavior rabbits need to engage in to ensure they are healthy. When a rabbit owner finds themselves with a heavy chewer (which is many, haha) and one who nips harder and more frequently than we’d like, a lot of patience and understanding is required to guide the rabbit towards what we consider “more acceptable” ways of communicating. Right now, your rabbit probably doesn’t understand the extent to what is making you frustrated… with exception of the angry pees. Some of those can definitely be intentional to signal they are frustrated, haha. And they want to show it!
First and foremost, I think the key word is “negotiate“– living happily with a pet rabbit means you need to negotiate in potentially several areas. Negotiations can mean literally re-arranging your furniture and modifying your behaviors, in addition to doing what you can to guide your rabbit to behaviors and activities you find more accepting.
You have “the foundation” covered, which is rabbit-proofing. It sounds like you may need to invest in some more robust measures (based on you mentioning he’s chewing all your cords. It is 100% your responsibility to never have them exposed to your rabbit or allow your rabbit to have access to them if you know he chews them). Especially with an active flemish giant, rabbit-proofing needs to be done pretty seriously to avoid injury and damage to yourself, himself, and your property. Rabbit-proofing, especially with a rabbit getting used to its surroundings, is an ongoing process. You observe, learn, and adapt. This can take a long time because the longer your rabbit navigates its space, the more it will explore and “test”. I’ve had my American Sable for about 10 months now, and I still need to move a thing or two because I realize “Oh no. That’s attractive to her.” or “Oh gosh, what’s that sound… ah! -scurries to block a wall corner and baseboard-“. I know of Flemish Giant owners who invest in baby gates to block off areas that are risky, and many rabbit owners in general may purchase rabbit-safe woods to install covers on corners, furniture, gaps/holes, etc..
In terms of the biting and breaking skin, I agree that it is important to see if you can identify what may be potential triggers for the aggravation. Some may be unavoidable, but identifying them is the first step to learning how to manage it and figure out the best course of action. One thing I’ll note is that if a rabbit is biting you out of spite or as a means to hurt you, it would definitely do more than break skin. My American Sable (about 5-6lbs), when I first rescued her, would also “bite” myself and my partner very often as a means of communication… and those hurt. And broke skin. Breaking skin is fairly easy for a medium to large rabbit to do. Their teeth are designed to destroy wood. I once was holding a hay mat for my Fable (my American Sable) because she likes a bit of tension as she digs and chews on the hay mat. To my mistake, I let my thumb get too close and with a simple graze of her intending to tear apart a hay mat, my thumb got a huge wound, that, once clean, was, to simplify, the deepest and widest paper cut I’d ever experienced that took weeks to heal. It was leagues different than her “bites” at my legs when she’s nudging me to move or get her food.
From my experience, distracting that energy elsewhere has been helpful. We used to have a couple piles of crumpled packing paper lying around where I sit most, and when Fable would get into a groove of coming up to nip my legs constantly, I would just keep holding some of the paper in front of her so she would chew and dig at that.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.