**This is... well... it's a bad idea**

The short (but not very valuable) answer to your question is yes, every one of those design limitations could be overcome.  But there's simply too many reasons why this shouldn't (and realistically wouldn't) be done.

* Roller skates work on firm, smooth surfaces.  They're usless everywhere else.  This would suggest roller skates on combat armor would only be useful in urban warfare, but...

* Streets and sidewalks are frequently filled with debris, especially after combat, which makes them little better than every other non-skatable terrain.

* To make things worse, bipedal combat armor has such an enormously high center of gravity that rolling along on roller skates would almost guarantee being tripped or simply falling over.  Consider rolling along, minding your own business, when a bomb explodes nearby.  Human reaction is to move one leg out to brace and keep one's self from falling over.  Dang... I had a roller skate on and in the fraction of a second of reaction time stepped out before retracting.

* They add complexity where no complexity need exist.  What happens when the bearings burn out?  Or a bolt breaks?  Or they simply get jammed with some wad of weeds?  This design, like the French [Chauchat machine gun](https://en.wikipedia.org/wiki/Chauchat), suffers terribly from small-moving-parts-in-muddy-weather syndrome.  And heaven help the soldier who experiences a failure in the retraction mechanism.

People can roller skate really well because they're not carrying armor and equipment and a ton of other material above their waist and they're basically only thinking about roller skating while they're doing it.  Distraction and a backpack of any kind and you'll be thanked by the enemy.

In the end, soldiers would simply never use the skates.