Is it possible to run the Mist browser with an external ETH client like INFURA? Yes, I understand this may not be the decentralized paradise we want to get to, but I'd just be happy to run a browser for now w/o having to download the entire blockchain. I understand I'll have to trust INFURA and I'm willing to do that for now.
To run Mist using INFURA, you need to start it from the command line
If you are using OSX, this is the command you want
/Applications/Mist.app/Contents/MacOS/Mist --rpc https://ropsten.infura.io
To use the main network, replace with
Also, you may want to try out Metamask, which is a Chrome plugin for connecting to Ethereum, managing your accounts, etc. (Metamask uses INFURA as a backend.) It's a faster UX since you don't have to download (and possibly sync) Mist.