You can just shoot from BUR to I5 along Empire. It gets a bit complex near the freeway but is signposted as I recall. Alternatively, go south on Hollywood Way to 134 to I5. It's true I5 can have problems but is not as bad as going through downtown.
Easiest way to find out if I5 is jammed is to go online or check KFWB 980khz AM which gives traffic every five or ten minutes. Then the alternative is to continue on 134 to 210 to 57 to 5. It is a bit longer but has more carpool lanes.
Under normal circumstances, I5 would be OK starting from BUR at 9:30.