To answer your questions in sequence,

Where there a lot of Scottish militants in the IRA?

• Yes and no, it depends on your perception of the person, while many Scottish born people passed through the Republican Movement (Collective term for the IRA and its political wing Sinn Féin) they would often be more considered as Scots-born Irish, ie someone whose parents were from Ireland but emigrated for some reason. The local IRA brigade to me had several such people in its ranks, with only one genuine full blooded scot ever being recruited.

During the troubles how was the IRA involved in Scotland? -The IRA avoided military action in Scotland for two main reasons, the first was political, they wished to frame their campaign as an anti-imperialist one against English domination and by refusing to bomb or carry out gun attacks in Scotland. This not only framed in as an Irish-English dispute but also showed that the IRA viewed the Scots as being in a similar position to the the Irish. The second reason was Scotland was a great place for fund raising for both the Republicans and the loyalists who would do money collections in bars and at football matches to take home and buy guns, by keeping the action out of scotland they could keep the police away from their cash flow. Loyalist organisation acted differently to the the IRA and would recruit some members in Scotland however.

Was their a Scottish resistance movement? -Scotland got a much better shake of being in a union with England than Ireland did, and by the time of the troubles in the North of Ireland a lot of the animosity between the two had fallen to little more than a petty rivalry, which isn't a great base to build a resistance movement from, especially a violent one but none the less the Scottish National Liberation Army was born. While it would make sense for the IRA to lend even tacit support to the SNLA, as they would do with some small cornish and Welsh groups the SNLA was so weak, badly organised and using tactics that the IRA disapproved of (Anthrax threats) that their offer of alliance was turned down.

In Northern Ireland the struggle was between "indigenous" irish Catholics and "colonisers" ulster protestants, often termed Ulster Scots. The latter identify more culturally with Scotland than with England, or southern Ireland.

In large parts of Scotland there was a similar situation which was restricted mostly to football rivalry and associated violence/hooliganism. However in Scotland the protestants were the "indigenous" while the scottish catholics were almost all descended from irish immigrants.

Therefore to be scottish and sympathetic to the IRA/Irish nationalism, was to think of your irish catholic ancestral identity as opposed to your scottish identity.