(Note: I don't get to talk about mixing / Reaper with anyone IRL, so get ready for a lot of words and excitement).
For mixing live bass in reaper, I really love the Bass Professor MKII plugin, which should be included in that ReaPack JS pack I linked to in the other post. It's a pretty intuitive EQ with some compression/distortion options built in. It's definitely not transparent, but I tend to like the color it adds. Can be good for cleaning things up and finding a nice pocket for the bass.
The mix on the first track sounds like it was fed into LANDR with too much high end (or LANDR just sucks, haven't ever used it so I don't know exactly what effect it has) or just was sent to Soundcloud at too high a volume. I tend to leave about -0.5 db of headroom on mixes that I post to soundcloud and bandcamp just because I seem to get some artifacts in the high end if I dont. I would also just recommend rolling off the high end on the drums with a filter - I would say somewhere around 20K is a good place to start.
If you still have an unmastered version of the first track, I'd love to hear it - kind of hard to give mix notes the way it is now.
Track 2 is definitely cleaner, but I think it could use a bit of modulation here and there for interest - particularly the bass, just because the bassline doesn't change all that much. Also, bass is a touch loud - this particular type of bass occupies a pretty huge EQ range, and can be really overwhelming if it's too high in the mix.
Also, I would personally try and get the drums a bit wider, whether that be through a slight ping-pong delay on the snare or by having the hat move around a bit. Actually, in general I think you can mess around a bit with delay / panning more, it seems like a lot of your width is coming from reverb, which can make things a bit muddy.
Sidebar: are you using a Korg Volca Beats for your drums? I only ask because I have one, and that snare sounds veeerrry familiar. In any case, I would consider mixing in either a clap or a live snare sample to beef up the snare a touch.
The main lo-fi synth pad (comes in at 0:24, not sure how to describe it) is really cool, but seems to have a bit too much high end to me (maybe around 1-3K or something?). Also, it's a bit muddy - could you tell me how you're processing it?
I think it would sound great with a bit less reverb, and I would try out the "delay (floaty)" JS in ReaPack, you can get some awesome trip-hop effects by messing with the warp function.
I think the reversed drum (?) at 0:50 is a bit loud, and lingers for a bit too long (though it might sound cool if you sidechained the kick into a compressor on it). Something I tend to do with reversed sounds is have the reversed sound fade into the original sample - e.g. have a reversed snare play almost all of the way through, and then fade into the original sample at the peak. It feels like it has more impact to me, and I think it's easier to give it a defined rhythm that way.
Sorry this feedback is a mess, and I hope it doesn't come off as too critical - this is some cool shit, and I'm looking forward to hearing more of your stuff!