Clicks and creaks can be fiendishly difficult to trace & cure. And despite a SS being "simpler", actually adds a dimension. I think I'd start by checking the chain for tight spots and binding. If nothig else, it's pretty much the only check that doesn't require disassembly.
You say you lubed the BB? Does that mean you have a cup & cone BB? C & C BBs do need a bit of preload to behave themselves while pedalling. You can't go for that finger-tight feel that might work for (nutted) hubs.
If it's a cartridge BB, then greasing the threads, or even a few turn of Plumber's tape before assembly is a common recommendation. If you have assembly grease(graphite, copper, aluminium - as used for brake pads in cars etc.), that can work better.
Then just continue to work your way through the bike. Pull the chain ring off, clean and lube mounting points, reassemble. Try another pair of pedals.
When you're out of the saddle you're usually pulling harder at the handlebar - something in that region might actually be involved too.