Is it way more busy and built up in KL?

i'M NOT REALLY GOING FOR THE SHOPPING – More for the beauty and culture – and nightlife!

And could I fly from Penang to Bali and Singapore?

Is it cheap enough to just find accomodation when I get there – or best to book in advance?

I want a budget place…..would there be any apartments with my own kitchen?

yeap of course as penang is an island where u can see n enjoy the beautiful sceneries along the seasides.whereas KL is all high buildings only n less green(trees).furthermore it's always traffic jam in kl.

yeap u can fly from penang to singapore n then transit to bali.
it's better to book it in advance thru travel agency.
yeap u can rent an apartment with furnished kitchen.