Hi @Hrithu-O.A !
I've reached out to you via e-mail but also will cover some of your questions here in short form:

I am working on a rather small project and setting up a programming module seems really intimidating.

Yes, the Programmable XBee modules can be intimidating but they are merely a standard XBee radios with included HCS08 CPUs that can be programmed for different smaller tasks. Digi does expect you to buy a separate Dev-kit and only supports Windows as the development OS. My blog post is about showcasing that you don't really need that for smaller projects and that you can successfully interface with the module outside the Windows operating system.

Can I add a programmable module to a network of unprogrammable modules? Will it be compatible?

Yes, and yes. The radios are fully compatible. The programmable XBees only have the extra application logic that you can have on the HCS08 CPU. The radio module runs exactly the same firmware as the non-programmable variants of the modules and have the exact same configuration options. You do need to have a XBee shield with a reset button to be able to access the bootloader of the module to successfully configure the XBee radio settings using XCTU.