As to your questions:
1. We indeed had such a bug when RadGridView got stuck once it had 143 rows and it was successfully resolved some time ago. May I ask you to test with binaries with version 2014 Q2 SP or with the latest internal build and let me know the result?
2. Regarding RadTimePicker - indeed, we have such an issue in RadTimePicker, I've logged it in our Feedback Portal, you can track its progress at the following link:
As to the second issue - I wasn't able to reproduce the reported behavior, could you please send us more details/some sample code?
3. Please note that the RadMaskedNumericInput internally uses nullable double (double?) variable. This is why we suggest using the same type of variable in your custom logic. As for visualizing 1 when the value of the control is set to null, I could not reproduce this behavior on our side with our latest official release. The value fallbacks to 0 if the binding cannot set it due to failed conversion.
As to your last question, would you please share some more details, for example how do you define the visibility of the row details on the different levels? Do you notice a visual glitch
you would like to remove? Would you please attached an image to illustrate what do you mean?
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