Thanks for reaching out with these questions. 

Hydrangeas: Some varieties of hydrangea bloom on the new growth, and some bloom on last year's growth. It is critical to know which variety you have to determine how and when they should be pruned. If your hydrangeas are in the latter category, then the type of hard pruning you've described means that they will not bloom this year. They'll have to grow back up again to create the stems for blooms next year. There's a handy chart that can help you determine which kind you may have: https://www.provenwinners.com/sites/provenwinners.com/files/pdf/hydrangeas_demystified_2015.pdf. 

Forsythias: Generally pruning a forsythia should not harm the shrub, but young plants should be pruned minimally. They're vigorous plants, so the pruning you've described shouldn't be harmful, and they should grow back fairly quickly. They are sometimes grown as a hedge, which sounds like type of shaping the landscaper did. If it was already blooming when the top and sides were shaved, then chances are low that flowers will fill in the bare spots this year, but it should recover by next year. Getting them back to your preferred shape, however, may take a bit longer. 

Liriope: Removing unwanted spreading liriope can be serious undertaking if it has gotten out of control. Since it spreads by runners, getting it back within the the confines of the edging is key. Anything that has invaded surrounding beds would need to be removed by digging it out, and the longer it's unmanaged the more difficult this task becomes. This process may also need to be repeated over several months until it's back under control. 

Overall, none of these issues should be permanently detrimental to your landscape. If you find out that the hydrangea is a variety that blooms on old wood, and they cut it back drastically, that would definitely be something to point out to the contractor. That being said, if you are unhappy with the outcomes, then you might consider communicating to your landscaping contractor (if possible) what the expectations are, what your landscaping goals/vision are, and any special considerations that they need to take into account in order to ensure that, going forward, they're not damaging or altering plants in a way that is not desirable to you .