I mean, the thing is, these lenses are SLOOOW as balls. Yeah, they're cheap and they're probably fine - especially for video, but yeah, unless they are exactly $free.99, I wouldn't go looking.. Seems like a lot of bullshit for lenses that are varifocal and slow. The focus ring and hard stops are pretty attractive, however - that is a huge plus in comparison to M4/3 lenses with awful electronic MF.
I'd say the 20-60 might be worth it if you're actually going this route, and then just add a cheapo Canon FD or Minolta 50 or a 28 or something. You could put together a pretty decent lens system for around 30-40$ that way.
and for the lens cap thing... just find some old sigma Nikon caps. Those things were super long.
Honestly, if I was doing this (and note, I like shooting primes), I'd just get a 24 or 28, a 50, and buy the m4/3 14mm f2.5 and call it quits. Wouldn't cost someone much more than 200$ for such a kit, and it covers the more popular focal lengths. It's not like the 14-42 is that expensive either if you needed a zoom..
So yeah, I wouldn't go through the trouble for this unless they are virtually free. There are tons of cheap old lenses out there for mirrorless cameras.