Your bass I think is int he right range.. but needs more movement.. you can try modulating the volume using an LFO (or vibrato) or double it up (ie use a second oscillator) and slightly detune, creating that phasing/undulating feel... I notice this instantly makes the bass come alive..
regarding synths... I remember having the same problem when I started out. I discovered that synth sounds tend to chew up a LOT of the spectrum, particularly the high end.. so applying a low pass filter to shave off those higher freqs generally helps you get a more natural sound overall. Also, it helps to find what other elements are interfering in the spectrum and use sidechaining. Example, if the track has vocals that can't be heard because the synth is taking up that bit of spectrum, I'll set up sidechaining on the synth channel so it lowers the volume when the vocals come in.