Hi,
Maybe I'm not the most suitable forum member since I'm more in integrated design than system level but here I go:
I haven't worked with MURS but making a google search I found that it's FCC regulated(
http://www.provide.net/~prsg/murs_faq.htm) so your filter requirements should be derived from the spectral mask dictated in the rules
http://www.provide.net/~prsg/mursrule.htm#95.635, from this requirements you could trace a asymptotic filter and derive the order.
You could place a filter between the IC and the gain block and another between the gain block and the switch, it depends if the IC generates spurs that could be useful to filter prior to postamplificate, and then you could filter again to be mask compliant.
I've checked the datasheet of both the IC and the block gain(quick reading) you specify and maybe I'm missing something but accordint to ADF7021 the output power of the internal PA it's 13dBm and the CP1dB of the gain block it's something like 2dBm at your band so I think that it's not a suitable block for this application.
For the receiver filter it applies the same, the order it's determined bby the worst case of unwanted emission. You should check the rules and see how much power will be outside your band then determine the filter order.
Hope it helps,