Just read over my Answer and TL;DR warning I guess!
Will filling cracks with resin visually add or detract?
Totally a personal call. Some people don't mind open cracks (somewhat depending on how open they are) while others seem to need any and all cracks.
Filling cracks opens up a range of possible decorative choices, from the very common dark brown or black to something that will stand out, to make more of a feature of them, so strongly coloured, filled with crushed semi-precious stones like turquoise, or metal powders including stainless steel, nickel, brass or bronze.
Would filling with 105/205 West resin add any real strength?
Not in surface checks. Yes for cracks that run through, but butterfly keys or anything similar probably add greater reinforcement that is more likely to endure in the long term.
Note that if you don't like the look of butterfly keys or any alternatives they can be installed on the underside and not the top.
I just bought the slab and while it seems thoroughly dried, I'm uncertain as to whether new cracks will inevitably form due to the type of wood that it is.
Best to adopt a wait-and-see position and leave it in your working conditions for a while. If your workshop has lower humidity than where the slab was last stored (reasonably likely) then I'd bet more cracks will show, or one or two of the existing ones will open up further.
Now how long to wait... well that's partly up to how long you can wait, but given the thickness I would suggest at least a couple of months.
How does one fill the live-edge side of the slab with resin while avoiding bleeding of the resin into the wood surrounding the cracks?
A good tip is to lightly finish the surface of the wood around the fill site1. Excess epoxy won't penetrate much or at all and will be much easier to pare, file, scrape or sand from the surface as well. Shellac is probably the best choice for this, although you can use other finishes and they'll work equally well shellac can be applied very accurately by brush and dries really quickly so virtually no wait time before you can proceed to the next step.
The bleeding normally of course needs heavy sanding to remove
Just to note, on any flat surfaces planing or scraping are other ways this can be done and it's easily argued are better choices for the usual reasons (if you need just one good one, speed alone is enough to prefer them to sanding).
While some sanding of the surface is almost certainly going to be needed regardless of the approach taken to get the majority off it reduces it to a minimum which is a good general position to adopt.
General thoughts on how best to approach this slab to bring out its full beauty/potential?
Oil or an oil finish are the ideal finishes to bring out the full beauty of wood grain. Even when using shellac (including full-on French polishing) previous treatment of the wood with oil is common as it increases contrast and enhances chatoyancy to the greatest degree, often now referred to collectively as "popping the grain".
If you'll be finishing in polyurethane varnish, or any other oil-based varnish, there's probably no benefit to oiling the wood in advance, but you'd should do a test to confirm this. Use the underside for any tests like this, or an offcut if there is one.
Just as a closing comment, this doesn't look like it was dried well and it's that which directly led to many of the cracks (one or two are often inevitable). If other pieces of similar wood from the same source show the same defects2 I wouldn't buy any from them again unless there's a price consideration.
1 You may have to treat the whole area, remembering that any wood treated this way will be partially sealed so any penetrating finish used for final finishing won't colour it the same as untreated wood around it.
2 While the current taste often sees cracks as 'features' it shouldn't be forgotten they are defects and good, careful, drying methods largely avoid them. Since cracks are defects they should be a factor in pricing so look for a discount when any number are present.
