Yes, chilis should be dried out before you use them. For me its been shelf-stable outside for 2-3 months. Obviously, with botulism you would smell it right away if its off.
1) You can't smell botulism bacteria
2) Oils are notoriously shelf stable
3) Botulinum bacteria need oxygen deprived environment and relatively stable ~10°C to proliferate.
4) Botulinum bacteria spores must be present in the bottle
