I am not up to speed no all of this, so please excuse my question. But if the other traders are so deceitful, then why trade with them?
If you scalp all day and you would rather bid a little over .05 instead of going all the way to .06 (say to get out of a short), that penny can add up. One cent on five thousand shares is fifty bucks............If you're doing this all day and you're only really trying to make five, ten, fifteen, twenty - five cents.....whatever, this stuff adds up. Nothing wrong with being efficient.
When you see them doing this to you, try this.. Put in bids/offers the opposite way you want to trade, then when they jump in front of you - pick them off. You do run a risk of getting hit yourself, but in a slow mkt this can work pretty well.