1. Yes, the internal tool is VERY basic and will not do most of what you want for reporting. It is very useful for some things but not a real report writer to replace CR.
2. Look at the example Crystal Reports, they show how tables are linked together. Once you get used to it the format is really good and is fairly logical. It takes some getting used to but this will be one of the easier things you need to do.
3. No way that I know of.
4. The only reports I found useful from LANDesk was Incident and Change. Nothing else was useful.
There are a few questions you did not ask that I will also answer:
Is Crystal Reports any good?
Yes and no. Yes it has lots of features and can do just about anything. No in that it is very difficult to learn, is poorly organized, is not logical, and will often make you mad at how hard a simple thing is to do.
What else is there?
In the future (near?) there will be other options but I have not seen anything official yet. Rumor had it there might be a new internal report writer coming. Personally I like SSRS (SQL Server Report Services). It is much better laid out and far more logical. I only have two reports in it so far but I like it far more than CR.
If you have someone that already is an expert in CR then I might stay with that. It sounds like its support within SD will not be going away even if something new is brought in. Maybe we will get an official announcement soon about a new report writer. All I know is that we already own and use SSRS because of other departments and I have been very happy with it.
Maybe it's worth giving both a try and see which you like better. I can tell you every time I used the Internet to find a CR answer, I found as many sites with answers as sites saying how they hate CR. SSRS is a typical Microsoft program, nothing super fancy but it gets the job done and it has a nice interface.
It will be interesting to see what others think. A lot of the above is personal opinion and others might have a far different opinion.