harvs, I work in education and often wonder about DD's articulation. I'll often say that I know what they are supposed to do from 4years up but have no idea from 0-4. The things that you mention sound largely developmental (I know R and L sounds develop later) but a hearing test is never a bad idea. The lady who did DD2's newborn hearing test said she thought all children should have their hearing tested every 6 months.
As to the things my DD1 does - I now realise that I don't know specifically which sounds she can't do but I do know she has some sound substitutions. The thing I notice the most is that she has difficulty with words that begin with 's' particularly in consonant blends, such as 'stop' and 'stick'. She often transfers the s to the end of the word so it becomes "tops".
I find her understandable about 80% of the time and others about 40-50%. If I'm concerned about her speech I repeat the word back to her a few times and may ask her to listen and repeat it.