once its cut in and you have some styling product in it you'll be surprised how much better it will look and you can work on getting a better blend from there on.
As for the red you can tone it down with colour conditoners as mentioned but some will be from how the hair reflects the light differently from your own hair i find using a matte product helps.

I colour my hair and the system hair with wella professional hair colour kit which uses somthing called a colour drabber which also tones down the red hues in the hair.

the knots may not be that noticable if you don't shave your head right down and leave some stubble thats what i do i only shave down to a grade 2 and looking at the density you have somones really gotta be looking i reckon.