Tintin, here is my issue altogether with just relying on explanations from websites. Those websites are unchallenged sources. Someone can say whatever they want and they won't be challenged there unless they have a unmoderated comment system in place or something of the like. This gives them free reign to post any strawman argument or unsatisfactory argument they want. Thank you though for posting the links this way. Posting an overall link and having to make your opponent search through and find your own sources actually points to laziness on your part. This link posting is much better.
With that being said, I'd have to say these defenses really leave something to be desired. It's as if the author was pulling at straws to find any possible explanation. As for the mustard seed. The bible says that Jesus said it was the "smallest of all seed." According to the link you sent, the only explanation they give, is that Jesus must have meant more contextually, that it was the smallest seed in the area or the smallest of a certain group of seeds. So what they are basically doing is adding to the Bible. They are adding on an assumed contextual specification that there is no evidence to believe in. This kind of defense is no defense at all. I can go to any quote in Scripture and say, "oh yeah, Jesus said this statement, but then he probably said something else afterwards to clarify it so that it fits my point of view. It just didn't happen to make it into the Bible." See how dumb that sounds? Without going on and on about what Jesus could have said to narrow the seed pool, all we can look at is what Jesus did say as recorded in Scripture. And from what is listed, we can say that Jesus was wrong in his assertion that the mustard seed is the smallest. He either didn't know, or if he knew, he spoke in a deceptive manner.
Also for the rabbit chewing the cud. It's only defense is that it is not unreasonable for people in ancient times to see a rabbit chewing and think he is chewing the cud. But remember. God is the one who said this. So God was mistaken? He was confused? He saw a rabbit chewing and thought he was chewing the cud? This explanation does not satisfy anything at all, but makes God out to be someone who doesn't even understand his own creations.
And as for the four-legged insects, the defense there is pretty much the same one you already gave. The Mantis' forelegs look like they are arms, so that's okay to call them arms. But remember, God is talking here. Is he confused about his own creation? Since dogs and cats use their forelegs to hold onto prey, do dogs and cats all of a sudden have two arms and two legs. If some middle aged man 4,000 years ago was writing this stuff, I'd give him a break here. But this is supposedly God speaking. It's a little concerning that he would make these mistakes.