Sometimes you will have a wingy cat. One of my family pets when I was growing up was very verbal so it can just be that the cat likes to have his voice heard! Although if you are worried then definately take him to the vets to check there are no problems. Maybe he doesn't like the way you pick him up or it could be that he has an injury so maybe try being really gentle and see if he still does it. (I'm sure you are gentle anyway!)
Does he wriggle to get away when you're holding him? I have a cat who doesn't like being held and he sometimes grumbles. Maybe he's just telling you he'd rather not be carried.
In terms of the grass, yes cats do need access to grass. Eating Grass often occurs when the cat needs to clean out its stomach by vomiting (maybe to get rid of furballs!). If your cat does not have access to grass, house plants (which can be dangerous) or anything similiar will be used by your cat. Vomiting will oftn occur soon after the cat has eaten grass. It has been said that cats also eat grass to obtain "Folic Acid", something that cats need in minute quantities for its well-being. "Folic Acid" cannot be obtained from their meat so they seek it out elsewhere but my reading on this suggests that it's eaten usually for digestive purposes. You can buy seeds or trays of cat grass which you can leave or grow in the house which will do the trick.
If you put 'cat grass' into ebay there are loads of seeds you can buy on there which are very cheap and I know my cats love it! My cats go outside but I have a pot of cat grass for them which they adore.
