Besides the obvious issue of you having too much information to load onto the SSD, I've done this basic procedure in the past. However, it's much easier now using Time Machine, but you have a few options:
Time Machine
If you don't currently have a backup that can hold all your data, do yourself a favor and pick up a drive that can. Time Machine should be built into the OS you're currently running.
Do the backup. For 400 GB, you probably want to set it up before you go to sleep and let it run overnight. Once it's complete, unmount the drive and unplug it from the computer. Go through with the drive install and then install Lion. When the computer reboots, before you start to work with the setup assistant, plug in the new drive. At some point it will prompt you for a location from which to migrate data. Select your backup. Let it run for a while and when you get back, it will contain all the data you backed up, in a usable form. This is my current favorite method for cloning user workstations.
Super Duper
If you can't get an external backup, you can use SuperDuper to create a full-system backup from the active system disk. You'll have the ability to trim the data to the size of the disk to which you're copying in the interface. This route is a little more technical and requires a bit more time hands-on.
File Copy
I wouldn't recommend copying a user folder for a logged-in user due to open preferences files. You'll get all kinds of "File In Use" errors and it will probably exit the copy prematurely. Instead (if you're dead-set on using this method - which I advise against) create a second admin user and copy the folder over into a temporary location before staging it into the actual /Users/ location. You'll also need to make sure the permissions for the entire folder are set so that the user whose home you are copying can actually access and write to their files. To do this, you can use the Finder's Get Info on the folder and then add the user to have full permissions. Once it's staged into the /Users/ folder, you can log back in to the main user and delete the secondary admin. You may have permissions issues in the future using this method.
All that said, it's totally worth it to get an external to back up to for Time Machine to clone your new SSD from.
If you're using Migration Assistant, the software will stay licensed, and if you intend to wipe and repurpose the old computer it's likely you're in the clear as far as licensing goes.
The Windows guest OSes won't notice any change: VMware's virtual hardware won't change, so they'll be totally oblivious to the migration.
I know from past experience that Microsoft Office works fine after Migration Assistant runs. I'm not sure about Serene Screen or VMware, but I've never had any trouble with any licensed software after Migration Assistant, including notoriously picky stuff like Photoshop or LabVIEW.
Now, on the other hand, if you simply want to clone the software and use it on both machines, you could probably get away with using the same keys, but you should check the license to see if that's allowed. If it's not, it should be as easy as buying a new license key and just replacing the old one on one machine.
Best Answer
There are no special steps. Install it using the installer just like you did on your old Mac. When prompted for the activation key, select "activate by phone" and input nothing, keep trying and it should provide a number to call.
Microsoft (unlike Adobe) does not have an automated system for licence deactivation. This has been a point of great angst among Mac users as it requires them to call Microsoft each and every time they move the Office application from one machine to another.
I believe the number in the US is: +1 (800) 936-5700. Your product support number may vary.
Here is a rundown on activation and product key information.