The display options you have chosen are OK on their own.
If you're looking to get more speed out of the code, try only graphing the data every 10 iterations or so. You can save the processed data (your waveforms) in a shift register where they can then be appended every 10 iterations.
This will obviously not clean up your code. The best way to clean up your code might be to simply throw the conversions you're performing into a sub-vi. Or create a time input for your "meters" VI and have thr processing done there with correctly-scaled values being outputted.
Hope this helps
Shane.
Using LV 6.1 and 8.2.1 on W2k (SP4) and WXP (SP2)