So if we were to view the visible spectrum of a white dwarf star. Would the planetary nebula essentially block what would be an absorption spectrum? If so, would we all just see emission lines. I'm not too versed in this topic so forgive me.
I think that planetary nebulae are "optically thin" at almost all visible wavelengths. That means a photon emitted from the white dwarf will pass through the planetary nebulae with little probability of absorption. Thus the visible spectrum of a white dwarf at the centre of a planetary nebula will look just like the spectrum of a "naked" hot white dwarf, except it will have some superposed (forbidden) emission lines arising from optically thin gas in the planetary nebula. Even then, any emission from the planetary nebula is easily distinguished from absorption lines in the white dwarf atmosphere, because the latter are pressure-broadened by the high surface gravity to large widths, whereas planetary nebula emission lines are very narrow.
An exception might be in the early phases of planetary nebula development when they can be thick to ionising radiation (basically in the UV region though).