Cryptic Family Reunion: Accentuate the Positive

The answer to this puzzle is a list of ten thematically related words or proper names or phrases. Each of these is clued cryptically, and the theme is to be determined. Since the definition part of a cryptic clue would give away the theme, these cryptic clues use a family member (e.g., mom, sister) to stand in for the definition part of the clue. So for example, if the theme of the puzzle were chemical elements, "Sister picking at nit" would clue "tin". Clues are sorted with answers in alphabetical order, and lengths of each answer are given with the clues. I hope you enjoy!

1. Brother welding a copper tube with no filler (5)
2. Nephew's honorary promotion appears baseless (5)
3. Able to lift or flip son (5)
4. Mom gives everything up after rolling dice (7)
5. I read novel Parade's End with little sister and niece (9)
6. Viagra vendor is stocked for Grandpa (5)
7. Daughter to eat stuffing from cookie (6)
8. Dad's strutting right out the door (6)
9. Uncle losing his way after turning 50 (8)
10. Auntie off diet to eat Lemonheads (5)

These are

diacritical marks.

Brother welding a copper tube with no filler (5)


ACUTE: A CU T(-ub)E.

Nephew's honorary promotion appears baseless (5)


BREVE: BREVE(-t).

Able to lift or flip son (5)


CARON: CAN containing OR<.

Mom gives everything up after rolling dice (7)


CEDILLA: ALL< after DICE*.

I read novel Parade's End with little sister and niece (9)


Viagra vendor is stocked for Grandpa (5)


GRAVE: substring.

Daughter to eat stuffing from cookie (6)


MACRON: MAC(-a)RON.

Dad's strutting right out the door (6)


OGONEK: right = OK, out the door = GONE, and GONE is "strutting" OK in that it stretches between its two halves as a strut stretches between the two sides of a roof. (I think.)

Uncle losing his way after turning 50 (8)


OVERRING: ERRING after VO<. (I have to say I think that's a little naughty: taking "50" to mean "a 5 and then, completely independently, a 0" is a bit like taking "cutest" to mean Cu=copper + test. Clearly this didn't make it unsolvable, though :-).)

Auntie off diet to eat Lemonheads (5)


TILDE: DIET* containing L(-emon).

Maybe it's also worth pointing out:

"Accentuate the positive".

• Re: the one you're missing...on the right track...think about putting a comma somewhere in the wordplay. Re: naughtiness...the good kind? :-) If not, please explain...and please believe that is a genuine request, not seeking an argument. I will admit I like to clue up to the edge, but do not want to be unfair. Thanks! Commented Jun 3, 2020 at 20:01
• OK, I have a guess at how the missing one works, and I've explained a bit more (in the relevant spoiler block in my answer) about what seems a little naughty. Commented Jun 3, 2020 at 20:06
• Thanks for the feedback! I get what you're saying re: naughtiness, and will keep it in mind moving forward. Not saying I'll never do it again :-), but it's good to have markers. Re: the other clue, rot13(lbh'er onfvpnyyl gurer, ohg V jnf hfvat fgehg nf n ireo gb vaqvpngr "fhccbeg", yvxr fgehgf va n pne). Commented Jun 3, 2020 at 20:38
• rot13(Gb zr, "fhccbeg" fhttrfgf pbzvat yngre va n qbja pyhr, engure guna orvat va gur zvqqyr.) Commented Jun 3, 2020 at 21:49
• rot13(V'ir frra fhccbeg, naq hfrq vg urer, nf n pbagnvare va erirefr beqre, r.t. N gnxrf O orvat fvzvyne gb O fhccbegf N. V qrsvavgryl frr lbhe cbvag gubhtu. Gunaxf!) Commented Jun 3, 2020 at 22:48