Honestly not against the loop idea actually. I'd probably do this though:

15 - Replacement 42 bus service (Hourly)

16 - Wallsend -> Hadrian Park additionally serving Wiltshire Drive via 41 route, 335 route to North Shields additionally serving Murton, 11 route back to Howdon (Every 30 Mins)
17 - Reverse of above (Every 30 Mins)

18 - Byker to Benton (Every 30 Mins)

19 - North Shields to Cramlington via new tender route (Hourly)
19A - North Shields to Killingworth via current route to Northumberland Park, current 335 route to Quorum (Hourly) extended to Killingworth via K1/K2 route.

57 - Cramlington to North Shields Ferry via Seghill to Whitley Bay then 11 route to North Shields (Every 30 Mins)

W3, 333, 335, 59, 59A, K1, K2 withdrawn.