Cong! You can email him to show your appreciation. Perhaps later near the year end , you can post-mail him a new year's greeting card. Money gift is not appropriate.
My lawyer revised the letters one by one, but he asked me to hold onto them without getting any signature before he took an overall look on all of them. He made some minor adjustments to make sure that they complement each other with enough diversity in the style, wording, etc, before I sent them out for signatures.
No. The paragraph in the reference letter to talk about themselves with their achievements are good enough. CV is unnecessary, but it's better for you to check out their websites and write that paragraph in the draft, and then let them verify and expand.