Since I play small venues, I was wondering if my 800 keyboard speakers (2x22) and a small powered sub would sound like a full pa system. Comments appreciated.

I have done that tons of times, going all the way back to my KORG 15s up to the PA800 ... the on board speakers are "so close" to being enough for many jobs, and adding that sub, or even a small bass amp - adds the necessary fullness to make the system appear about twice as loud. No need to overdo the bass - just adding a speaker on the floor really fills it out.
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this could be perfect & versatile for your small venues on the floor with the kb speakers also..sounds great

The BA330 sound good, but not really enough bass to justify the cost for me. If it was more balanced, I'd still have one - it's a great mid-range option that's light and easy to work, but if you want bass .... keep looking.

looks pretty cool , I use QSC K-8 speaskers but if i wanted battery powered speakers these might be perfact now we need a battery powerd arranger and we are ready to do street shows.

the battery is an option top the AC power cord also.....
the BA330 is a real Swiss Army Knife....be careful with just a Sub & those KB speakers it can lead to a iffy unbalanced offset sound vs a full frequency unit.But heck...what do I know?

Perhaps for an acoustic guitar/vocal duo group, but no way will 6.5" speakers (x 4) + tinier tweeters (x 2) are going to cut it to reproduce the full range sound an arranger keyboard with bass & drums demand. A Logitech Z-2300 system @200watts RMS will deliver far better bass sound (though admittedly weaker mid-range), is of comparable weight, and costs a lot less than the $650 BA-330. I paid $99 for mine a year or two ago. Not sure if the Z-2300 is still in production though.