The halberd was quite common by the XVth century, there are plenty of paintings showing troops using halberds. Some are armoured some are not armoured. There was no rule determining that halberdiers should be armoured or not.
However, I don't know any unit that has a halberd and a bow. You may be referring to the one that has a partisan and a bow. Historically, pretty much every soldier had both a bow and another weapon. Usually a bow and a spear or a bow and an axe etc. Soldiers used to shoot their arrows, then drop the bow and pick up the spear or polearm or something like that. Mod engines don't really allow for that so it's the best we can do. Even the monastery images you posted show all the saints having both bow and another weapon. The one we chose is the partisan
The mace known as the 'maciuca' was literally the most common weapon that peasants used. It was literally a wooden club with nails in it, due to the fact that they were usually just pieces of wood they were very unwieldy and had to be used with two-hands. The club was pretty much a universal peasant weapon. Just google the word 'maciuca' and you will see it definition. http://www.upm.ro/facultati_departam...TM5_Part59.pdf
There definetly was no sicas or falx weapons. That stuff is ancient weaponry long gone. But there were scythes and sickles and axes and other agricultural elements.
The 10,000 Venetian armour was probably an exageration but they would have been worn by the boieri and the princely guard, all heavy cavalry. There is no way of knowing exactly. No one knows, we just make assumptions and educated guesses based on the best evidence we have.
Again, a lot of the cavalry had both spears and bows, most depictions have them using both. But there is really no hard and fast rule. In the XVIth century they even had lances and arquebuses
If you really want to do good research i suggest going to antique book stores and get 'Istoria Militara a Poporului Roman' Vol II and Vol III. These books were published by the military in the 1980s and include detailed descriptions of troops and weaponry. You will just have to ignore some of the obligatory idiotic communist language in the book.