I had a cheap solder sucker a while back, they're good for bulk solder removal, especially around big through hole components, but these days I just use wick because it gets cleans off SMD pads nice.
Leaded solder makes it a bit easier, but I used it a bunch as a kid and I don't recommend. You should either transition to lead free after you learn the basics or just start with it. Also use extraction if you use leaded.
I use Duratech leadfree, its pretty good, but I'm in Australia so you probably cant get it [99.7% Tin 0.7% Copper and 2% flux]
I only ever use my stands sponge and water for tip cleaning, only worn out 2 tips in like a decade.
I had one of those exact magnifying stands, they tip over in a gentle breeze, something like https://www.amazon.com/Third-Soldering-Workshop-Non-Slip-Aluminum/dp/B079CHJQKH?th=1 would be better I think. [I haven't used one]
sd:/_nds/nds-bootstrap/screenshots.tar
They're stored inside the TAR, like a zip without compression, so open that with a program such a 7-Zip.
To remove individual screenshots, just replace them with unused ones, don't actually delete them. nds-bootstrap relies on the size of the tar being exactly what it expects so actually deleting any of the files inside will break it. If you've filled up the screenshots then probably better to just extract everything from the TAR then delete it, then nds-bootstrap will make a new one.
Don't use Notepad, it uses CRLF line endings and might even put a UTF-8 BOM at the start, both of which will break GBARunner2.
From the GBAtemp wiki: > NB! The text file will have to be in Unix (LF) file format. On Windows this can be changed with a source code editor like Notepad++ by right clicking 'Windows (CR LF)' on the bottom status bar of the window and selecting Unix (LF).
Notepad is just kinda terrible and I would recommend avoiding it whenever possible.
Try reformatting with the SD Association's SD Formatter then follow dsi.cfw.guide's instructions instead of partitioning
Basically any GIF will work fine if you just resize it to 256x192 or smaller using a tool such as https://ezgif.com
For making your own animations... I haven't really done that, but just look into making a video / animation, then convert it to a GIF and resize it if needed.
I'm not sure the exact steps in anything except Hex Fiend (macOS only) but just like scroll to where the offset (usually numbers on the left side) is 3900 and select everything from there to the start, then delete it.
I ordered a 64G "SanDisk SDXC I" that works. You'll just need to download a formatting application that can format in fat32 before using it. Here's the Amazon link, for the 128G: https://www.amazon.com/dp/B08GYKNCCP/ref=cm_sw_r_cp_apa_glt_fabc_RKDH1YA7VSPG63Q96RVV?psc=1
Wish I reas the Q&A section before buying the r4. The consensus is it sucks for anything but SNES (which tends to be glitchy, I wasn't able to fix it. Just is what it is) https://www.amazon.com/dp/B07YL762C9/ref=cm_sw_r_u_apa_fabc_rt50FbDDW6CS7?_encoding=UTF8&psc=1
I don't know much about that, but normally they should all function properly and be all compatible with the DSi.
I bought This one and it functions pretty well. Just keep in mind that if you're looking to install DSiWare games, you should mod your console which is done easily.