As for looking obsolete, I disagree, but that's a different topic entirely.
Photo editing and video editing on Linux has come a long way in recent years. Keep in mind here that getting functionality comes first over ease of use a lot of the time in the Linux world. While it's not as bad as ten years ago, there are still a lot of programs that work best once you get into the mindset. This goes for professional tools on Windows too, however, and is generally becoming more accepted as far as I can tell.
If you're looking for basic photo editing, I think GIMP is overkill for sure. It's built as more of a powerhouse of photo editing features rather than something for quick edits. For those, I can recommend Shotwell. It handles more like iPhoto rather than Photoshop, and is targeted more at people who don't want to spend all day learning that one program.
I can echo the positive sentiment around LibreOffice, although I'm a little puzzled as to what makes Calc inferior to Excel, there have been many times where I have reached a specific feature quicker in Calc than Excel simply because despite more complicated control panels, the interface is easier to navigate. I've put people with no experience with Calc who have only used Excel behind it and they generally get things done a little quicker, with the same or better results. I've never used macros in LO or MSO, however, so I can't speak to which one is better.
Video editing is tricky. Some perform differently on different platforms, and it all depends on what you're looking for. I'm going to split this into two categories, beginner and professional.
Beginner: KDEnlive. (Simple, less crashes, supports multi-thread rendering, I think basic compositing, though I haven't used it as much as the next one)
Professional: Blender (Includes 3d modeling, transform strips, raytrace-based photorealistic 3d, compositing, the list goes on...)
Vector graphics is another one where it's all about workflow, like with photo and video. If you want all the tools, Inkscape has given me the best luck, but Libreoffice includes Draw, which seems targeted at flowcharts, Calligra includes Karbon, which is probably more friendly in interface, but I hardly know it, so I have no idea, and there are probably more I haven't even heard of.
Audio is possibly the most multifaceted part of your list. Here's what I use, based on the task I'm using it for:
Quick, cheap edits: Audacity
Live sound: Ardour
Sequencing: LMMS
MIDI: Haven't in a while, but Ardour again
Sheet Music: MuseScore
All of the audio applications above (except Ardour) are also available in Windows. Ardour is available as well on MacOS.
Honestly, I do believe that aside from security (which is generally better across the board, though not impenetrable) and speed (which is mostly improved, though their are areas Windows can do better), Linux is notable for how well it allows scripts and odd setups. Keeping this in mind, it isn't a far fetched expectation for you to install all of these and still have a stable system, so experimentation is probably your best bet.
I hope some of this mess makes sense and helps, good luck!