an alternative arduino ide ?

Atom with PlatformIO is good option. But I'm prefer to use CLion, and using Arudino-CMake to enable arduino aupport for CLion.

Or a lighter and better option to use iotor with CLion, Atom or any ide/editor that you like.

After initializing, adding or deleting files run

# in <project>/build dir
$ cmake ..

When you want to upload:

$ make upload