9a Tbilisi - 'is it' (holding) 'Lib' (all back)
11a Guns - 'snug' (comfortable, about)
16a Apache (helicopter) - 'pa' (returns) + 'ache'
1d Insignia - anag 'is gain in'
2d Slain - 'SaLvAtIoNs' (regularly)
15d Charity - 'chary' (wary, about) 'it'
23a Bottom - double definition