i vote for raspberries near walnuts. funny story: theres a walnut in my dad's front yard and when i was like 10 years old i randomly picked up a walnut one day and threw it over my house and it by chance hit my dad square in the head! that's like a 1 in a million throw, i couldn't see him, i wasn't trying to hit him, i just was 10 and throwing a walnut over the house was fun so i did it and bam! and i got grounded!!! for having bad luck i got grounded!!! which means i couldn't go outside! which was torture cause at 10 all i wanted to do was play with bugs, which 99% of were outside.
Anyway yeah I vote don't cut down walnuts, they evolved good way to ensure the survival of their species, don't punish them for that, grow stuff that resists their stuff near them, and you can grow the rest out of range since you said you have enough room.