The barebones TG-16 unit needed to succeed pretty well by itself before we could ever talk about expansions like the CD-ROM.
Absolutely.
The Turbo would not have done any better with more games. The hucard library is sweet, but consoles really need a watershed, genre-defining game to catch on. Something like SMB, which revolutionized platformer play control and forever standardized which button on a controller makes you jump... or Sonic with its jaw-dropping beautiful graphics and speed. The PCE doesn't have a hucard like that. It had Ys, but that was on CD and the technology was too much, too soon: kids couldn't afford CD players.
In Japan, I get the impression that video games were already fairly mainstream entertainment in the 80's/90's, which meant that older people played them who could afford cutting-edge technology like CD video game players. With the exception of the Neo Geo, video games in the States were regarded as toys until the Playstation came along, which doomed systems like the CD-ROM2 and 3DO until the technology got cheaper.
On a personal note, while I'd certainly love to have some more English games on the shelf in 2012, I never would have got into the TG16 had it been #1. Had it been popular, it wouldn't have been discounted down to $99 and I wouldn't have been intrigued by a mysterious black console with library of hidden gems and diamonds in the rough. Apparently I have a huge underdog complex.
I thought they already were in third. Who are you counting in the third spot? NeoGeo? CDi? 32X?
NES was 3rd; TG was 4th.