Most of what should be said here appears already to have been.

1. Case trimmer. No contest. Faster, cleaner, and you determine how much to take.

2. Corncob media. Yeah, it's annoying picking it out of flash holes, particularly in small cases (i.e. .223). But, it's cheap, lasts awhile, and cleans cases as well or better than any walnut or other tumbler media I've used.

3. I've used standard RCBS dies (incl expander plugs) for years to reload pistol and rifle cartridges. Never an issue.

I started out about 25 years ago with a RCBS Rockchucker kit (press, Uniflow powder measure, case lube kit, deburring tool, loading block, and 5-0-5 beam scale.

Since then I've added a tumbler, bench mounted case trimmer, caliper, RCBS Universal Priming Tool, Primer Pocket Brush, a baffle for the powder measure, RCBS Powder Trickler, and am using Stony Point/Hornady gauges to determine seating depth by firearm.

I'd also recommend obtaining a chronograph. Chrono'ing a string of test rounds will yield valuable data that may help you weed out inconsistencies between your reloads that cause poor performance (particularly accuracy). Did I mention case prep, case prep, case prep?