Rhyme time quiz.

[furrypusscat]

Due to a possibility of more postal strikes and wishing to send this quiz off, I am asking if anyone could help me on my last two which I have been pondering over for some time.
Qu 7a - Not secure (10) answer rhyming with stradivarius.
Qu 21b - Swine thief with a musical parent (3,3,3,6,3) rhyming with run.

Qu4 I have epicoene for the answer thinking it is an anagram of 'one piece' can anyone confirm as I don't know if this is correct.
Thanks in advance.

[Jan1957]

7a Precarious

[Jan1957]

21b Tom Tom The Pipers Son

[furrypusscat]

Thank you Jan1957 for your quick response. I much appreciate your help.

[chestnut]

QUESTION 4 - I HAVE UNBROKEN RHYMES WITH THE 2nd part

[furrypusscat]

Thank you chestnut, I think you are more than likely right on that one. I couldn't see beyond an anagram, but I must admit it didn't make any sense.