wouldnt be to concerned about the smell as some strains have very little smell.
the reason your plants leaves are yellow and dying is because you are not feeding it enough nutrients or basicly a nitrogen deficiency some flowering nutrients have very little nitrogen which is why its not uncommon to see some yellowing late in flowering it sound like the nutrients you are using has sufficient nitrogen and that you are just not feeding it enough.
would suggest you start feeding at the same strength as you have been just an increased interval like every other watering or if you only water once a day or less you may want to feed every time you water the plant and you may be able to increase the strength of the nutrients on future grows wouldnt try it on this one as its getting close to being done.
a few days prior to you harvesting you will want to quite using all nutrients and just use water.