It's been a long while since I've been on my road bike, but I agree - 70 is slow; 90 is more like it. Ride in the smallest gear you can for the terrain and speed you want or you will tear up your knees.

Too many people don't have the bike set up right - do it at a shop if you cant figure it out. I see casual riders with the seat way too high and not set right - again, something that will chew up your knees and your wrists if you have too much weight on them.

Get clipless pedals if you don't have them yet. I use Shimanos but there are others. I got a cheap pair of pedals from Bike Nashbar years ago and a pair of Shimano shoes at an LBS on sale.

The Allez is a nice bike -old school. I've got an old aluminum Univega with Shimano 600 running gear, similar vintage, I bet. I see the Allezes for sale on eBay and Craigslist fairly often.

Needless to say, wear a helmet. I've had a few crashes and been hit by a car, so I know it won't solve everything, but at least it's something.
Don't get me started, you know how I get.