>The Coles were "low of origin, in trade" and Emma had intended to snub them by refusing theri dinner invitation

So was Mr Weston.
"He quitted the militia and engaged in trade, having brothers already established in a good way in London, which afforded him a favourable opening."

IMO these contradictory feelings of Emma as shown to the reader by JA is to confirm that these feelings don't run deep in her.

Another example is the Coles' invitation. After giving us detailed description of her thoughts we are told that going to the dinner won over, because like all young girls 'fun' dominated the other feeling. So, in conclusion, these feelings of 'low origin' are there, but are soon overcome with other 'better' things.

>Condescension! (the word most often used to describe Lady Cat in P&P)

The word 'lively' is also used for her - so is she like Elizabeth?

< I think Emma, like Darcy, had been "given good principles", but was also spoiled and "left to follow them in pride and conceit"

No, Emma wasn't given any education of 'superior' feelings as Darcy was (by his parents). Emma just caught it in her childish way while growing up - I suppose.

>Darcy had to meet Elizabeth before realizing that, while Emma had Mr Knightley.

Not at all. Emma belonged to the same class as Mr Knightley. She doesn't end up marrying Robert Martin ;-)