I'd prefer no 3 as I like bikes with clean lines not cluttered up with pumps, bottles, saddlebags lights etc... But very much individual taste & the kind of bike you have along with its purpose.
#2, Mini pump in a Jandd Tire Bag II as the bag holds 2 tubes, patch kit, tools, cutdown tire levers, small spares, mini pump and I can still zip it closed.
I have my tools in a fake bottle tool container on the downtube because I don't want to spoil the lines of a clean seat post / Saddle no space for cannisters though but I've previously discounted them because I don't like the idea of bodging the patches (which has happened many times) and running out if cannisters. Maybe time to reconsider...
Easy.
If the bike has built in clips/pegs use them.
If not and its old use bolt on chrome clips.
If its of an age whereby the more modern frame fit pumps existed use them.
I am assuming an older bike as you posted here so no mini pumps please.
If its one of those frame fit Zefals it isn't old. I hadn't seen any of them before the late 70's.
the list needs to be expanded
3.
...
C. attached to the seat tube with a Terry's Clip
D. attached to the seat tube with a clamp attached to the braze on
E. or use the other specialised fittings for the period CO2/Nitrogen pump.