First of all, if you write a post like this, chances are that nobody from Nokia will see it. If you have concrete, specific suggestions, then the Maemo Community Brainstorm site is the place to go.
Please pay attention to the emphasized words above - anything else just pollutes the list.
Examples:
Good:
- Add an Equalizer to the Media Player (concrete and possible)
- Add option to disable automatic addition of contacts (use-cases help)
Bad:
- Fix all bugs (Not possible - everything has bugs. If a specific one annoys you, then file a report at bugs.maemo.org (after first checking to make sure it hasn't been filed already))
- Better icons (Subjective and not concrete)

Also realize that programming and design work is a lot more complicated and time-consuming than you might think if you haven't done it, and often there are technical constraints. Thus, things like "increase frame rate of video capture" is probably either not possible, or was done for a good reason. Things like "add portrait mode for all apps" fall in the bad category too - good user interface design isn't easy, and trying to make an app useful in portrait mode as well as landscape isn't always possible or practical. If an app has a strong use-case for portrait mode, then the developer might look into it, but it's not as simple as just "enabling" the feature -- e.g. it should be technically possible to manually rotate the screen, but if the app isn't set up for it, it will probably just break the interface.
Feel free to make suggestions, but please keep this in mind, and -- especially -- if a developer tells you it isn't going to fly, then don't push it... these people are giving away software that they put a lot of effort into, after all.
Cheers,