Thanks for the Link Raggy (Term of endearment) but readers of stuff on the internet should not believe everything they read, incendiary shells apart here is another glaring error from the link you supplied:

"Ravaged by sniper fire, machine guns, nine-pound guns from Trinity College and 18-pound shells from the gunboat the Helga, the insurgents were forced to abandon the GPO and set up headquarters in 16 Moore Street."

The guns mounted on HMY Helga were 12 pound QF guns firing fixed ammunition. According to reports she fired on Liberty Hall and on one of the bridges which he hit with her opening fire, Liberty Hall a building used to print James Connolly's newspapers was also used up until the start of the rebellion to make bombs, grenades and bayonets for the Volunteers. As both Liberty Hall and the Bridge were located on the river Helga would have been firing on direct line of sight. The 18 pounders referred to were Army Field pieces. The Helga would not have carried incendiary ammunition as it has no naval gunnery application.

As to addressing your questions Raggy, would it make even the slightest bit of difference if I did answer them? Been down that route with you before and found it pointless, in any case they were all rather irrelevant having no relation to what was being discussed. By the way indiscriminate fire is when you just blaze away in a general direction for an indeterminate time with no attempt made to identify or hit a specific target. Targeted fire is when you identify, aim and correct if need be to hit a specific target, for a specific purpose.