We rapidly get the idea that W captivates Marianne & her mother, & engages Elinor's good will due to his appearance, bearing, enthusiasm & agreeing with everything Marianne thinks. The idea one gets of him from hes own actions & words, as provided by JA is interesting.

Of course, his first action is to get the injured Marianne into the house, out of the rain. That was a good thing to do. Of course, it cost him little effort--he picked up a pretty girl & carried her down a hill--not exactly Purple Heart material. It would have been indecent & callous to do otherwise, not to mention that her rescue probably provided some diversion in his day.

The first direct quotation we get from W is a disparaging comment on Col. Brandon: "Brandon is just the kind of man... whom every body speaks well of, and nobody cares about; whom all are delighted to see, and nobody remembers to talk to."

He then trashes Lady Middleton & Mrs. Jennings: "Who would submit to the indignity of being approved by such women as Lady Middleton & Mrs. Jennings, that could command the indifference of any body else."

He gives Marianne the horse--that's somewhat generous, but not exactly prudent given what he sees of their establishment. When Mrs. Jennings is teasing Elinor about "Mr.F" he opens the pianoforte to help deflect attention from her--that's polite.
Tnen, he takes Marianne all over Allenham without the permission (does he even have the knowlege?) of the owner,exposing her "to some very impertinent remarks."

I find the passage in which he expresses his affection for Barton Cottage as it is & tells Mrs. Dashwood that she must not alter it an expression of his arrogance. I know it's meant as evidence of his esteem of Marianne & the role the cottage has played in their relationship, but I find his manner of expressing it disrespectful.

Finally, just before he rides off in his carriage in Chapter 15, his last words express not care & concern for them generally, or even Marianne individually: "It is folly to linger in this manner. I will not torment myself any longer by remaining among friends whose society it is impossible for me now to enjoy."