Staccatissimo = shorter and sharper staccato than normal staccato. Almost like an accent in some cases.
With tenuto, tenuto staccato and portato it can vary a bit with the context. With Tenuto marks only I'd think of them as slight accents in a legato, so that the notes sound slightly separated/distinct from each other, not just bound into one gesture. Think of it maybe as three down bows instead of playing three notes in one bow on a violin, but still connected.
Tenuto staccato I'd read as the same but with shorter notes, but not too short.
Portato with the slur is also shorter notes but not staccato. There is more of a feeling of one line even if the notes are separated, but the notes are not made distinct like when you think in accents.
Don't know if that helps.