Resize Arcane Blast debuff
 

Is it possible to resize(larger) the Arcane Blast debuff icon shown in this attached screenshot?

Hmm Ive not thought about those being resizeable but worth checking if resizing those are similar to resizing the cooldown bar icons. But I know the latter is a file change compared to a slash command change.

Yes... you would need to edit [ Interface > AddOns > nUI > Layouts > Default > HUDLayouts > {hud mode} > nUI_HUDSkin_{hud mode}_Player.lua ] and search for ["Aura"] -- there's only one aura section [1] in the player skin, so you just need to increase the size of those auras.

However, keep in mind when you make the individual auras bigger, you make the whole aura frame bigger which means it will start to overlap the pet name, etc., below it... so you may need to decreate the number of rows and increase the number of columns so the aura box still fits in the available area.