Very nice clear pictures.  I see no reason why you should be concerned about having to reduce the size.  Note that if you do, the resultant images must be at least 4mp.

If I was being ultra critical (and SS might be), I'd say this:

Your coin might be rejected for flat lighting and possible incorrect white balance (needs more contrast).

The plane might be rejected for poor lighting (too many deep shadows on the plane itself).

In the hand and currency shot there is evidence of noise on the thumb.

The box with days and pills might be rejected as 'not commercial'.  Very difficult to see the point of this shot at thumbnail size.

The mobile phone is covered in dust spots and needs to be cleaned.  Note also that a designer buying this shot will be very disappointed to find the near and far edges out of focus.  It's difficult shooting these Motorolas because of their length, howeber if you place a couple of coins or something under the hinge to tip the phone unit slightly towards the camera you'll bring the rear edges into focus at F32 or preferably F64 (if you have it on your lens).

But I am being very picky.  IMO once you have been accepted at SS a batch of shots like this will sail through the approval procedure (apart from perhaps the coin and plane).  Overall, nice clean, clear pictures.

Hope this helps.

Additionally to what was said above:

- thrid image has paper structure visible in the shadow which can easily be taken as a noise. IMO, eliminate the shadown completely to be on a safe side (dodge it out). You may want to replace this one at all, it's questionable by other parameters too (focus, commercial value)
- on fourth one I would clone out a few black hairs on the finger... sorry, just looks unappetizing
-  fifth may require a bit different framing, it's shot so close that it takes a little to understasnd what it is... maybe just me being slow
- sausages on bbq, background is too dark IMO, high chance of "uneven lighting" rejection
-  shadow under the cellphone - same comment as for the third shot regarding the paper structure   

I personally hate the bug (eleven). Wierd DOF, feels like rather artificial selective blurring. Liking the broken egg (twelve), maybe framing to include entire yolk would make it even better? Check 13 for blown highlights, hard to tell but seems like there are some on white stuff on top of it (butter?) As for the rest, one question... why don't you close apperture a bit to get entire subject in focus? After you are in, experiemnt... for first 10 go safely, this "your focus is not located where we think it should" is fairly subjective thing, why give them reviewer too much freedom of choice?

Personally I wouldn't submit any of those to any agency because of the selective focus.  You've used F5.6 on the last one and you need to be stopping way, way down beyond that.

You might find that they can get accepted.  But buyers will be put off by the lack of overall sharpness.  In the world of art, selective focus is great, but in the world of stock images everything needs to be sharp.

In the world of art, selective focus is great, but in the world of stock images everything needs to be sharp.

Depends. If it's an isolated object, yes. If it's more like part of a scene and you want to draw attention to the focus, it isn't. The "art" of stock is looking with the eye of the designer, I guess. This one is from a batch of 30 of today, of which 28 where accepted. Most is out of focus here (diet lunch hour):