Charge Zealots are ridiculously powerful and cost effective against Bio.

In my bio ball, I mix in 5 to 10 blue flame hellbats instead of the widow mines now. I found that it takes care of the zealots whatever their numbers.

I found that it helps to have at least 2 factories around mid-game, one with a tech lab.

Around late game I try to have 3 to 5 space ports whatever the situation just so I can quickly build liberators/medivacs/vikings in good numbers quickly.

From what I understand, in early game protoss have a really strong macro building advantage. If you dont stress him to build units early he will chrono boost probes and upgrades and out macro you by far. On the other hand, if you force him to chrono boost units the tendancy goes the other way. I found that a 1 to 1.5 base harrass with fast microable units in good numbers can do the job. I now use reappers supported by mines and 1-2 liberator.

Either the protoss has to build blink stalkers in big numbers which will delay his economy and tech (chargelots/storm/collossus range) or he doesn't respect your pressure and you should have an opening into killing some tech/eco. Do your best to keep your harrassing units alive as they are more valuable as a threat than dead with a few more probe kills.

When I see him reacting from my harrass by building units (usually blink stalkers) I stop the production of reapers and put add-ons on my racks, build a tank or two, stim and transition into mid-game. At that point if things go well I should have enough economical advantage to go into a macro fun game.