quick advice needed

I just found out my brother is out shopping for a crossbow.
He's had a compound bow for years, and wants to upgrade to a crossbow. He hasn't been researching the market on modern archery gear in the last 10+ years, so he's like a newbie. His compound bow is 1980s vintage, but it works well.

What are some good features to look for in a modern crossbow?

He wants to scope it and use it out to 100 yards, if that's possible. But he knows that he'll be using it in thick woods where he'll not likely have a clear shot at an animal more than 50 yards out.

Are crossbows adjustable for draw weight? His compound bow is, and when he doesn't practice with it much, he has to lower the resistance quite a bit until he gets back in the groove.

He would be awe struck by a 2000 year model compound! A 2017 model would probably be too much to comprehend!

A crossbow is great for someone who doesn’t practice much.

With that said, has he shot a newer bow? You say he can’t handle the draw weight because he doesn’t shoot often enough. A 50lb 340IBO would be faster than whatever he’s shooting and would be a dream to pull back.

His old Bear or Hoyt bow is the kind that has a 50% let-off rating.
He can adjust the peak draw weight from 45 to 70 lbs.
But at 70 lbs, he can't pull it, and if he can sometimes, he can't hold it steady to aim while holding the 35 lb. force.

So what should be be looking for in a crossbow?
What features?

He's seeing a lot of numbers that relate to arrow speed.
But since we're talking about short little crossbow bolts, they have to weigh less than 29" long standard bow arrows, right?
If they weigh less, they'll fly faster even with no extra force pushing them.

If he's expecting to shoot at 100 yds with a crossbow, he'll be disappointed. Keep it inside 50 and he'll be fine. I practice out to 40, but rarely shoot at anything further than 30. That's with a 3 'pin' red dot sight. Don't know that id trust a grouping beyond 40-45 yds. 150lb Horton with 20-in bolts. Shooting Rage 2 blades.

The 10 point line is great for the money and what I would buy if I couldn't draw a real bow back. But I'm not a crossbow guy.

Scary!