a few weeks in, a few questions

Hi. I recently got a RTLSDR v4 and a Lilygo T-Embed CC1101 Plus.

I mostly connect the RTLSDR dongle on my NAS and use rtl_tcp to consume the data remotely.

I have a few questions:

• I'm using SDR++. I can connect to rtl_tcp just fine, however I need to set the rate to 1MHz or higher, using the default 250KHz results in some kind of "choppy" data. I'm confused: I understand that this "rate" is the bandwidth that is being captured in one go? Why is it called sample rate and not bandwidth? Why would 250KHz results in choppy data but higher values seem fine? Can I capture the same bandwidths with rtl_tcp or directly with the dongle on the processing computer? I can only zoom out as wide as the selected bandwidth, correct? I thought I had seen videos of folks showing that they were scanning hundreds of MHz in one go?
• I can monitor a frequency and send signals on that same frequency with the T-Embed and I can see data popping up. Great. Now... If I monitor a frequency with rtl_433, I'll see plenty of signals showing up. If I record a signal with the T-Embed then replay it, I never see it show up in the rtl_433 log.
• I built myself a Yagi-Uda antenna for 868MHz. Works nicely. I also have the 2 pairs of dipole antennas that came with the RTLSDR v4 (one extends from 3-4cm up to 13-14cm I think, the other from goes from 20+cm up to 110cm or so). What do you recommend I should get/build next?
• So far I've only tried picking up sensors in the 433 and 868 zones. I keep seeing folks posting weather satellites imagery. I'll build the antenna I need for those, but... what software do I need to decode such data? Any other fun such data to try and grab?
• Question on Tetra: is there anything to listen to with an SDR? Or it is worthless because encrypted or whatnot?

I realise my questions are rather vague but any pointer/tips would be appreciated!

Thank you!