Well there's no need to correct my english error in the text you quote
I'm sure you understand the concept, and usually i write faster while i'm thinking. English is not perfect but i'm sure i'm able to write understandable things :-)
Question is simple :
if you want to buy or sell to another user you can simply use the buy/sell pool.
did you see this image in the Tips & Tricks C.A.T. Section??
Using (edit manually) the buy/sell pool you can put some coins in wait status and let CAT use them to create new orders.
You can manipulate the buy/sell pool rules to use only some of that coins every lookup.
For example, you can put 1 BTC inside pool, but tell cat to create only ping with qty < x (maybe in some markets, with a quantity limit of 100, using 1 BTC you can creat 50-150 Orders).
And you can also tell cat to stop ping creation if 10 orders are active. (10 it's only an example, all of these parameters are customizable)
Every pool lookup (that occurs every number of normal lookup, by default 5) CAT will get some available coins from the pool, and will create a new PING.
If algorithm is static, order will be static at the price you choose, otherwise it will be a Dynamic order.
So, i have no problem to remove the Limit price check, and allows you to buy/sell to yourself.
BUT if you only want to continously sell/buy to OTHER users, you can use the pool.
I think CAT it's not complex, really, but of course, there's needed to understand this schema.