I f you want a more life-like test or just not very fond of scripted load testing (which may or may not represent actual use cases), another option would be to get actual people to do load testing for you.
Mechanical Turk, Fiverr and UpWork are great places to find people to do that for you in exchange for a very small payment.
What’s great is, you can describe your scenarios, divide people in groups, ask them to carry out those scenarios (or ask some to just improvize and experiment), perhaps ask some of the to use multiple tabs, browsers etc.
In the meantime, you would be analyzing your kadira dashboard (especially livequery), server metrics and application logs.
Roughly 100 concurrent users on a single app instance will give you an idea about your app performance and bottlenecks. (If budget is a concern, you can get 100 concurrent users with as little as 20 people using multiple browsers)