Collect all routing tables
"ip route" only shows the main routing table; you may want to consider saving the other routing tables too. You can discover them with "ip rule" (whose output you already collect), and show them with "ip route show table $foo" (by default it shows "main").
Maybe something like this:
for n in $(ip rule | egrep -o 'lookup\s\b\w+\b' | cut -d\' -f2 | sort | uniq ) ; do ip route show > "ip_route_show_table_$n.txt" ; done