Not saying homeopathy is a cure-all, nothing really is. But whats wrong with stimulating the body's ability to heal itself? Eating healthy and exercise stimulate the body's ability to heal itself, same with a variety of teas, and other supplements. Plus, a number of people have built immunities to poisons and venoms by exposing themselves to small doses.
Enzymes work by having collisions between the enzyme and the substrate molecule. When they collide in a kinetically favourable way, the substrate binds to the enzyme and shit happens. So obviously, for a reaction to occur using this model, you have to have two things, an enzyme, and a substrate, in positions where they could conceivably collide.
To make this reaction faster, you can do a few things: make the molecules move faster (i.e. raise the temperature) or make more of them (increase the concentration).
The important thing to understand about solutions is that they are not made up of an infinite number of particles; while there are lots of them in any given substance, they are finite. That finite number, in fact, is avogadro's constant: 6.02x10^23 molecules per mole of substance. 1 mole is the number of molecules of carbon-12 in 12g of pure carbon-12. When chemists talk about concentrations of substances, they usually talk in moles per liter. That is, if a solution is at a concentration of 1 mol/L, for every liter of solution there are 6.02x10^23 molecules of solute in there.
The problem you come into is when you get into homeopathic dilutions. In normal chemistry, nobody would bother trying to dilute a substance down to such an extent. But homeopaths do. When they talk about solutions they talk about 20X, or 30X, or 50X. I think in a talk by James Randi he mentions seeing a solution of 100X.
In 1 liter of a 20X substance you are statistically likely to find somewhere in the order of magnitude of 6000 particles of said molecule in it. Even if the substance were botulinum, one of the most toxic substances known to man, you would not be able to physically ingest, or inject, enough solution to get enough molecules of it into you to have any effect, therapeutic or lethal, even if you could concentrate these molecules somehow in the body.
In 1 liter of a 30X substance it is unlikely in any liter of solution for there to be a single molecule of this substance in it. Literally the odds are around 1 in a million. In effect, you're now drinking plain water; in fact, I don't think even commercial water purification plants could guarantee a purity of water this high. This is to tap water what Intel's cleanest clean room is to a garbage dump.
In a liter of a 100X solution...if you did this all in one go, the amount of water needed for 1 mole of substance to get to this concentration would be inconceivably larger (more than 10^30 times, by my calculation) than the volume in the milky way galaxy.
So basically, you're kind of right in some ways. Where you're wrong is thinking that homeopathy provides this kind of treatment.