I haven't seen multi-range selections in code before and that looks like an interesting avenue to explore.
If you are looking for a 'magic' way to apply styles in PDF conversions, I would consider trying the Autoformat command which is as close to vba magic as I've seen.
Code:
With Options
.AutoFormatPreserveStyles = False
.AutoFormatApplyHeadings = True
.AutoFormatApplyLists = True
.AutoFormatApplyBulletedLists = True
.AutoFormatApplyOtherParas = True
.AutoFormatReplaceHyperlinks = True
.AutoFormatReplaceQuotes = False
.AutoFormatReplaceSymbols = False
.AutoFormatReplaceOrdinals = False
.AutoFormatReplaceFractions = False
.AutoFormatReplacePlainTextEmphasis = False
.AutoFormatPlainTextWordMail = True
.LabelSmartTags = False
End With
Selection.Range.AutoFormat
If that doesn't work, post a sample document so I can see what you are actually looking at.