Mute or proactively demote their hangover.

I highly recommend E-Wang Hotel on the corner of Xichang Lu and Kunshi Lu (昆明鹰王E捷酒店 ／ 云南省昆明市昆师路2号 ／ +86-871-63957000). No need to book ahead. Currently 179元 @ VIP rate (ask!), circa 200 otherwise. 24 hours. Very good location with 3 minute walk to Green Lake but not affected by the annoying one-way street traffic problem around it. At the quiet end of a major night time barbeque street food market, great for meeting people and practising your Chinese. Very easy to get taxis about town and in walking distance to major foreign restaurants and nightlife locations. Nice rooms with aircon. Two free bottles of water per day - ideal for alcoholics.

I had a very bad experience with Lost Garden and would strongly recommend avoiding it. I used to run a hotel reservation network across China and having signed contracts with over 3000 hotels around the country feel it's fair to say that in general hostels are not useful in China unless you really want to save money and are in a major tourism center... you are better off with a private room for a few extra yuan, especially as security is one of your priorities. The cheaper/smaller/odder places tend to all have weird annoying issues and/or eccentric management.

Get a registered taxi from the airport - I can't remember what the toll is these days, probably something between 60-150元 roughly. Meters are fair and drivers are honest in Kunming, so don't worry about being ripped off. It helps to have your destination written down in Chinese. The new airport is a long way out of town.

Sanya can't be too bad as a former Kunming resident American teacher friend moved there and has stayed for many years.

The interior of the island in particular has some interesting Austronesian/Tai history.

The weather in Hainan is probably better than Xiamen, and there is probably less pollution.

You can go sailing in either place.

In Sanya you can go surfing, have the option to learn Russian, and they speak Mandarin instead of Fujian Hua which will likely be better for the development your Chinese language skills.

If you are looking for stops in between Xianggelila and Kunming, I would recommend Baishuitai. It has nice mineral terraces and a walk in the forest above the town is breathtakingly beautiful. Since it's mushroom season the locals may take you up picking. You can climb 1000m from there, it's pristine Himalayan pine forest. From there you can continue to Tiger Leaping Gorge via Haba, and either get the ferry across the river or hike the gorge backwards (maybe even for free).

Past there, check out Shibaoshan. To get there, just get any bus headed toward Dali or Kunming from the western end of TLG, then jump off at the turnoff to Jianchuan. You want to get a bus down Jianchuan way, get a room in Jianchuan, then walk up to Shibaoshan yourself the next day. It's a fair walk but definitely doable return. Alternatively, stay in Shaxi and do it from there.

You could also look at visiting Jizushan northeast of Dali's Erhai lake, or even Chenghai or Lugu Lake (after a boat across from TLG's eastern end), instead of going to Shibaoshan.

Between any of those places and Kunming is Chuxiong, which is also a great place to be in mushroom season, and has a dinosaur theme park based on its fossil vein as well.

Definitely speak to the owners of Bad Monkey bar in Dali. The guy has a huge collection and is an escaped/retired professional classic car mechanic.