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About queue, expiry, scantime: Keep them default. I don't touch them and i have 0 issues with connectivity.
About worksize: Keep this @ 256. It has nothing to do with the pool difficulty, but rather GPU work unit. HD 7xxxx series cards appear optimized for -w 256.
About gpu threads: 7950s love gpu thread @ 1, with a high(er) Thread Concurrency number. 7950s appear optimized to run with 1 gpu thread and a high concurrency. Ensure that your thread_concurrency number is a multiple of 2 (2^n).
About vector: Unused, good for delete as you already have.
Your primary GPU related settings are: intensity, thread_concurrency, worksize, and gpu_threads. When you're using the config file format, tune those and leave everything else at default (unless a pressing need presents itself.)
I would also recommend setting your GPU fan to a constant 80-90%.