Most of your questions need to define the reason for VNAV SPD ie is the speed window open and where on the approach you are, or are you off profile with the window closed.
1. Yes if the speed window is closed / No if it's open.
2. No as its not on path to comply with the restriction, however the speed window is probably open for you to be in VNAV SPD or you would have recieved a drag required message or been in THR VNAV SPD below profile with the window closed.
3. I assume you mean you've entered the ATC speed restriction in the VNAV DES page while on descent. There is no change to the answers above ie once it's done the math at the new speed, it'll go into VNAV SPD if it is above or below the new profile, if below the new profile eventually it'll catch PTH, if above you'll get a drag required message. It may even catch PTH straight away, it depends how great the difference in the new speeds are and therefore how different the profiles are.
Note Entering 230kts for example will delete the 240/10000 as its now redundant.
Edit: Grammar stupid apple autocorrect.
Last edited by SMOC; 14th Nov 2011 at 10:34.