Yes it does get easier, as they grow out of some stuff (and my boy is at the severe end).
But you mentioned that your child is now imitating words and saying a few?
I was told something by a v eminent professor of ABA that I wanted to share with you.
He reckons that if an autistic child can imitate words, you can get them talking functionally, but the best and quickest way he has found to achieve that is what ABAers call the "echoic to mand" transfer.
Here is how he described it, with an anecdote from his own practice:
He was visiting a family whose boy had had only echoed speech for years.
As he talked to the father, he noted out of the corner of his ear that the boy was repeating or echoing the occasional one of their words, eg "swim".
He decided to go swimming with the boy. At the side of the pool, with the boy all excited about going swimming (his major love) the prof stopped him, stood in front of him and said "say swim" (but the "say" bit quieter, so as to be faded out soon). The boy echoed "swim" and they both jumped in joyously.
Then, out they got again, to the boy's disgust, but he got his reward of jumping in again when he echoed "swim".
Third or fourth time, Dr P did not prompt "say swim" at poolside, but just pointed at the boy's mouth expectantly. The boy said "swim". His first independent mand, or request. Immediately they both jumped in and had a long, joyous swim. Given that reward, next time they got out and stood together poolside, the boy knew to say "swim" again.
The next day he did the same drill, with a different highly-motivating activity - eg "chips". And so on.
Dr Pat ended by saying his heart bleeds to think of how many ASD kids there are globally, with echoic speech, but languishing in schools which just don't know this one simple protocol.
That would have been my boy, had he stayed in his Teacch school.
The mand training was the key, opening up in his little brain the synapse marked: different mouth movements get me different good results (= speech).