Interested in 320 Rebuild Information

I'm new to experimental aircraft and am surprised by a number of
things. The first was a peek inside a Lycoming IO-360. I've spent
most of my life around things mechanical...from building cars and
racing motorcycles so my first look inside a Lycoming was a surprise.

Given the size of the reciprocating components, it'd appear that the
engine beats itself to death before it wears anything out. The size
of the connecting rod pins, push rods, and valve spring pressures, on
the surface, seem to be way out of scale for a 180 HP engine.

Thin walled wrist pins that withstand 7000 HP in Funny Cars and push
rods that weigh in grams, not pounds that withstand 700 HP and 8000
RPM are common place, even in "hot" street machines. I guess what I'm
most curious about is why this technology, common place for 20 years,
is not included in certificated engines?

I was also stymied by some odd looking (excuse me for using the wrong
terminology) floating counter weights on the crankshaft. I'd expected
to see a solid, balanced crank. Can anyone help me understand the
advantage to have floating weights?

Why do you suppose they made the cylinder and head a single piece?
There are some pretty reliable, high horse power, high cylinder
pressure motorcycle engines that use a separate head and cylinder. If
the single piece was better, I'd expect factory race teams to follow
suit.

Any help would be appreciated.