I'm a big time walker 2+ hours a day while in Pattaya. Personally, I never counted on the sidewalk trees for shade.
I noticed the ladies enjoyed standing under the trees... that's probably the reasonI bothered walking there! For shade... the tall buildings up/down the Sois and 2nd Road did the trick.
Funny thing about those trees... the rats love"em too. Seen many a nasty bugger shooting up/down those trees countless times.
As for Pattaya Beach... I wouldn't put a toe into that water! Not in 2008, 2013 or now. The smell and filth coming from the beach is/was a detriment for swimmers. My experience with beaches... people are drawn to the water more than the sidewalk trimmings.
No reason you can't have both, but sidewalks are more for... walking, selling stuff and meeting people. I'm all for a good vibe, but I appreciate the wider spaces and improvements on the smoothness of the walkway. It was a mess tripping and turning ankles walking that sidewalk.
If they wanted to improve the beach (and they should) they might consider starting with the water and working back.
There weren't many beaches in Angeles City and the go-go clubs... well... they were unaffected.