Siberian: While Sublime does appear to quite good, it is also not a free program; if you are willing to buy it, fine. However, there are a wide number of free editors and IDEs available for both languages, starting with the venerable Emacs and going to such choices as SciTE, Komodo Edit, and (for Windows only) NotePad++. There are also many language specific IDEs, such as Eric and DrPython for Python. Being rather old-school, I use Emacs for most purposes, because it is far and away the most flexible and easily extended of them all, but the learning curve is high.
Might be a reduction of loading times. In this day and age browsers and even mobile apps can quite happily handle the addition of jquery. In most cases if you use the google link to jquery it will already be cached.
Yeah with python, I'm not too sure as I've never used sublime with it, but along with all the other snippets available on git I'm sure you can quickly integrate it into your workflow.
And technically sublime is kinda free. All it does it have a popup every week to ask if you wish to buy it. All you do is click no and you can carry on using it... all bells and whistles unrestricted. I guess you've never used sublime to know this.
As to whether this is ethically OK it's up to the programmer. There's no reason to say in the future sublime CEO might change this so I guess that might be an issue if you intend to use it for mainstream dev.
Every webdeveloper I know use and swear by sublime. Once you get on it you'll forget whatever IDE you used to use before. With the except of EMACs it offer the fastest and most complete features that I know of.
...And even for 70 dollars or whatever is says on the website, it is well worth it.