Is there a way to configure user account for different uses? I am a marketer by profession and am currently learning to program in AngularJS. I also like to make music using various programs.

For marketing I need Evernote, Skitch, and TextExpander running in the background.

For development I use a pomodoro timer, Transmit and a few others.

During music production I want everything off to save memory / battery life.

Then there are times I'm traveling and have to turn everything off while traveling.

Without having to create separate user accounts, is there a way to quickly turn on / turn off all the required apps for each use case?
You could set up Automator applications to do just that. For instance, you could go to Automator, select Application from the "Choose a type for your document" menu, and then use the Launch Application action to open all the apps you want. Once you've set up "Launch Application" actions for all the apps you want for a specific use case, you can save your application with the name of the specific use case, drag the newly-created application to your Dock or desktop or wherever is convenient for you, and then all your apps are just a click away!

You can also make applications to quit all of the apps in a specific use case. Automator has a "Quit Application" action too.