Hi Benny - sorry for delay in reply, I've just come back from a scouting trip.
As for Emei - if you've not already seen it there's a little info on my website -
http://sichuanbirding.cloudaccess.net/sichuan-birding-sites/32-emei-mountain.html
I've always visited the site with my own transport so really know just about nothing on using the park bus service. But I do know they don't make any stops apart from picking you up at the bottom and taking you to the top.
It's going to be very crowded - but there are still a few places that maybe less crowded. When at the top bus-stop walk down and get into the area called the ski slope - around here a lot of bamboo/rhododendron for stuff like Chestnut-headed Tesia, Chinese Wren Babbler, Red-winged Laughingthrush, Bianchi's Warbler, Yellowish-bellied and Abberant Bush Warblers. A little lower down there was a new road cut into the forest that made an extra loop to the top - last year it was still unfinished and made a good birding track with Sichuan Treecreeper, Black-faced Laughingthrush, Darjeeling/Crimson-breasted Woodpecker, Rufous-vented/Grey Crested Tits, Buff-barred and Sichuan Leaf Warblers and a lot more. On the very top there's an old monorail track - but access, the site has been blocked off, involves some furtive fence climbing. Here a lot of Bamboo with star birds being Chestnut-crowned Bushwarbler and Grey-hooded Parrotbill.
I'm afraid the two tracks which you can get to on the summit access road are only easily available if you have your own vehicle - The first is around 7km up the mountain from the point marked on my website's Emei sketch map as 'park-gate - start of access road to summit area.' If you were really determined you could walk it - but the bus traffic to the summit is pretty horrendous. However rewards are good - Emei Liocichla, Golden Parrotbill, Sichuan Bush Warbler, Emei Leaf Warbler.
Otherwise its walking on the main paths - the birds are pretty habituated to the crowds - but crowd noise can make it difficult to hear any bird song. If you walked down from the top you may eventually lose the masses -but that would mean hiking two days on the mountain with one night in one of the monasteries.
Dujiangyan is pretty good for birding. My last guest had a morning there a few days ago, and on Lingyan Mountain, which is very close to some of the main 'irrigation site' tourist attractions, we quickly picked up Grey-winged Blackbird, Great Barbet, Dusky Fulvetta, Black-streaked Scimitar Babbler and heard several Golden Pheasant. In the Agricultural University grounds we found Swinhoe's Minivet. Much of the tourist area will contain the type of habitat that gives decent birding - also watch out for Tiger Shrike, Brown-breasted Flycatcher and Rufous-faced Warbler. If you get the chance to go to the new Panda Center in Dujiangyan the birding in this area could be quite interesting.
As for local guides - all that I know have been long booked but it might be worth contacting Chengdu Birdwatching Society (listed as CBS in birdingpal).
Best of luck
Sid