Adapting to online assignments

We're making the big change to incorporate CCSS next year into our curriculum.  My district decided to go the integrated route and doesn't have money for new books, so we decided to use a program called Math XL instead. It's an interactive online textbook in which the kids are given problems to solve (and enter their answers). It has both multiple choice and short answer questions.

The Good:
1.  Kids get different problems (so copying homework is going to be much harder)
2. They get instant feedback on whether their answers are right or wrong
3. I can see how they did and how long they took on each problem.
4. There's some way to download the grades in Math XL and import them into our grade software. I haven't tried that yet.
5. You can also do tests/quizzes using this program.
6. Kids get used to doing math on the computer; a necessity since they'll have to do the CCSS tests online.

The Bad:
1. Technology problems... although after the first day of trying to get logged in, I haven't heard anything from the kids.
2. The program needs flash to work, which means that the kids can't use an iPad or phone. I found an app called Puffin that seems to do well, though it's $2.99.
3. This year I've been collecting student assignments randomly throughout the week. I'm not sure how to adjust this to work with Math XL. I told the kids that they need to still work on paper like they would normally (but then enter their answers online) and that I would randomly collect that. The assignments we've been doing haven't required much work, so I haven't done that yet. And then there's #4 which contributes to that, too.
4. Because I was worried about students having internet access, I've left the assignments open for more than just the normal one day that I would give them to work. And they're definitely taking advantage of that... some kids are getting behind and we're only on day 2.  I figure next year I'll be using this with freshmen from day 1 and can just set the standard that they do their assignment that day/night and that's it. No extra time. (The district plans to buy enough Chromebooks that each freshman will have one to use during the school day.)
5.  I often have time in class for the kids to start their assignments.  If they don't have a computer with them, that's wasted time.  So either they need a computer or I have to keep them occupied until the bell rings. (Again, the 1:1 thing should negate this.)

From thinking through "The Bad" I think I've found work-arounds for all of the issues that I've recognized in these past few days.  I don't know that I'll keep this program up for the rest of the year; I wanted a chance to see it in motion and get issues figured out before we use it for real next year.

So here's what I'm thinking for next fall for my freshmen:
1.  Open up assignments early so they have a chance to go through them before class if necessary.
2.  Require them to keep a notebook/INB with their work that could be collected at any moment.
3.  Close assignments before class begins the day after it's assigned (like a normal assignment).
4.  Maybe give a homework completion grade? I don't want to do this necessarily but I also don't want to look through everyone's work every day, especially if they're doing different problems.  This is obviously still something I need to work through.

If anyone uses MathXL (or something similar) and would like to give me advice or recommendations, I'm all ears!