Most of those aren't actually one effect: they're two.
- What does [thing] smell/look like. That's an Intellego effect targeting [thing], and it's Form won't be Imaginem. InIm spells are about manipulating your (or the target's) senses. This needs something like the InTe 5 guideline "learn one mundane property of an object."
- Make [other thing] resemble something else. That's a Muto Imaginem effect, targeting [other thing].
You can't squeeze them into one spell because the effects have two different targets. This is the sort of thing you need an enchanted item for, with Linked effects -- the item learns what the smell is with effect #1, then copies it onto something else with effect #2.
You can't apply Ring duration to make #2 indefinite unless [other target] remains within the Circle for the entire duration.