Sir,
1% duty is applicable "if the said excisable goods are manufactured from inputs or capital goods on which appropriate duty of excise leviable under the First Schedule to the Excise Tariff Act or additional duty of customs under section 3 of the Customs Tariff Act, 1975 (51 of 1975) has been paid and no credit of such excise duty or additional duty of customs on inputs or capital goods has been taken by the manufacturer of such goods (and not the buyer of such goods) under rule 3 or rule 13 of the CENVAT Credit Rules, 2004.
192[Explanation.- For the purposes of this condition, appropriate duty or appropriate additional duty includes nil duty or concessional duty, whether or not read with any relevant exemption notification for the time being in force.
If the imported gold bars are exempted from payment of CVD then the manufacturer cannot avail any credit. Under rule 18 of Central Excise rules, 2002 whatever ever duty paid on the manufactured goods whether at concessional rate or at full rate, the same is available as rebate.
Regarding query No. 2 the above explanation will clear your doubts.