Hi Alex,
Sorry for delay in replying.
1) You can set Color.FromArgb(232, 232, 241) for selected Cell which gives similar color with Color.FromArgb(127, 157, 185) of Alpah Blend. Please refer the sample for (3).
2) We are working on it and we will update you as soon as possible.
3) I am afraid that I was not able to reproduce the issue. Also I have created a simple sample to test this issue with 1000 rows and it is available in the following link
http://websamples.syncfusion.com/samples/Grid.Windows/72504C/main.htmPlease have a look at the above sample and if still the issue exists, could you please try reproducing it in the above sample so that we could sort out the cause of the issue and provide you a solution?
Please let me know if you have any questions.
Regards,
Asem.