ACROSS
1. T + (D inside MILITANTSWILL*) = TILT AT WINDMILLS <fight pointless battles>
9. PAN AC HE = PANACHE <swagger>
10. (FAR AGO) outside R = FARRAGO <potpourri>
11. WEEP after S = SWEEP <series of victories>
12. STYLI + STIC(-k) = STYLISTIC <concerned with literary technnique>
13. <regretted> RUED = "RUDE"
15. SO UV + L A K I = SOUVLAKI <Greek dish>
19. AB + (OL outside VEAL) = ABOVE ALL <in particular>
20. LEO outside G = LEGO <building material>
23. <fast-food place> DRIVE-THRU = D RIVET HR UV
25. <belligerent> AGGRO = AG + ←ORG←
27. <concert venue> STADIUM = MUSTAID*
28. EU + PHONY = EUPHONY <harmony>
29. UP(-o)NRETREAT* + RALLY = PRETERNATURALLY <as if by magic>

DOWN
1. TAPES TRY = TAPESTRY <woven artwork>
2. N inside LUGE = LUNGE <forward movement>
3. <swallow> ACCEPT = CEP inside ACT
4. <one giving an edge> WHETSTONE = TOTHENEWS*
5. <neat> NIFTY = N IF TY
6. <sweet> MARZIPAN = MA + (RAN outside ZIP)
7. (LEAST WISE) = LEASTWISE <at any rate>
8. S + (CONE outside C) = SCONCE <candlestick>
14. <stamp out> ERADICATE = E + (C inside RADIATE)
16. V + (TUNA + VOLE)* = VOL-AU-VENT <pastry>
17. <well-connected> COHESIVE = COVE outside (HE'S I)
18. T(-elc)O + PONY + MY = TOPONYMY <analysis of placenames>
21. A + (DUP outside DS) = ADDS UP <makes sense>
22. <encumber> HAMPER <large basket>
24. (-c)HUM(-s) + AN = HUMAN <individual>
26. <one with morbid humour> GHOUL = (-gun)G-HO UL(-timately)