You may want to remove Frozen Mallet. They reworked slows so that they don't stack, back in patch 5.13. Now, Frozen Mallet's slow won't apply to Meep auto attacks once Bard collects 45 chimes. Before that, you only gain an additional 5% of slow on Meep autos.

Here's a neat trick you could add to the Escape Artist section. It requires your ult and a flash, but it is perfect when there are already several champions on top of you.

You ult on top of the entire group, and then immediately flash out of it. The enemy champions will be trapped, and you will run away. This has a near perfect success rate the first time you try it (as long as you're not CCed) because they wont be expecting it. After that they will know what you are doing, but they will still only have a split second to react, and they might need to use their flash in order to follow you out.

Well i will go deeper into itemization but i haven't had the time to write it up.

That said, frozen mallet and or black cleaver are viable picks, but both very expensive.
RoA is a good all round item, it provides health for sustain, extra mana which converts into damage for muramana and the AP gives damage and makes your heals stronger.

Now i do agree that there are some better items especially for damage output.
Triforce, IE, or essence reaver. ( The last one helps to keep your mana up for muramana )

I hope this answers your question!

Is the RoA only there for the purpleness?

You'll likely be better off with a Frozen Mallet or a Black cleaver, especially if you are not rushing RoA.

Interesting pro's and cons

After some tweaking and fine tuning I've found a some what better build.