there are lefty bats to be had. stargell, yaz, Parker, mccovey, brett, morgan, jackson, cooper, powell, kemp, staub, mercer, oliver, aikens, b. williams, nettles, cash, mayberry, porter, and evans to name a few. add in some switch hitters like murray, singleton, smith and simmons and there are plenty of possibilities to be had.
As far as trades go - I am only at the nine game point in my two leagues - I have no Idea of what i have or need yet.
as far as the draft being predictable - i guess that I come from the 80s leagues for the most part and I am finding that there are a lot more options at every position with the exception of the middle infield. I think that this will create a bit of a drag on trades as well since it would be easier to fill a hole without giving up talent by just scooping up a new player to see if you can get a stud year from them.
sorry to hear that your seventies experience has been less than "groovy" I for one am enjoying the heck out of mine thus far.