You more or less have 10amps constant draw of protection. Going to 10a fast blow, and or an 8a s.b. would be a good move. In fact, keep dropping the value till you DO blow a fuse, then raise the value by ½-2amp; "depending". As low as possible protects best, fast blow protects best. Slow blow should be saved for "fine tuning" systems.
You shouldn't really count on switches to pass power to connecting rails. Even Lionel always suggested a power drop be run to all three sections of connecting rails; three lock-ons per switch. A drop to all three connecting sections of track should prevent this excepting maybe a fluke oddball derailment on the switch being ignored. The three drops give a heavy draw a path other than that trace. (I think it may also make the repair unnecessary 
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