Tricky:
My personal opinion...For example, on salsa and chips...Maybe try introducing tha beat tha way you did with tha strings in it and then after about 4 bars or so, either completely cut them, or strip them down and stab em in there on occasion so that it leaves more space for tha lyricist...tha strings are cool, but they sound very upfront and "lead" so i would make them your hook part...
On soft sounds, it really just depends on tha lyricist, cuz some fools jus know how to ride a beat, but honestly if you didnt want to cut anything at all, then you could probably let someone jus rap over it tha way it is...you never know till you try tho!...
My suggestion, is that: Your on tha right track, but when you start to feel that your track is feeling cluttered, start stripping it down and taking parts out and keep workin with it to see how it feels....Rule of thumb, is that in general, mind you this isnt set in stone...when tha hook part comes in is where an extra instroment either comes in or leaves...keep that in mind and it will help for more inviting transitions...
And last, keep working at it...practice makes perfect!....For right now try what i said, and maybe tighten up yer mix...
Good luck homie...
Steezo