1) The 3000x3000 limit for the Basic/Standard edition is a "features" sale point. The Standard program is essentially the same as the Pro with limitations.
Filter Forge ignores DPI and renders pixel for pixel, that is, if an input image is 4000x3000, the output is 4000x3000. You can adjust DPI yourself for your own purposes or resize in Photoshop or a similar graphic editing program.
2) Filter Forge 7 was just released, so updates will occur more often for now. FF requires that you have the latest version to download filters. Updates will be not be
constant, however. Updating will not affect your trial period, so if you have 20 days left before updating, you will have 20 days after updating.
Good luck with your testing!
Math meets art meets psychedelia.