What Skyrim clone? Bioware went back and updated BG1. The BG games are semi-open world. Those gamers were created by Bioware. Bioware did what some of their fans asked for going back to their roots. For example in BG1 after rolling for attributes during character creation the gamer did not get to add to or change the attributes.
The similarities between BG1 and DA:I are just superficial, and in most cases, only on paper. Exploration in DA:I, by how it's controlled and played, resembles Bethesda's style more than old Bioware. Big maps which require not only walking, but constant jumping, "exploring" with a search button and taking insane amounts of products to keep item based gameplay rolling. In BG you could change attributes at the beginning ad this allocation had a deep impact in the way the game was played. This has nothing to do with DA:I, and is a difference, not a similarity.
The only way the attributes change was using armor, weapons or accessories. The party would have to find an ioun stone to change any attribute. The ioun stones came in different colors which corresponded to an attribute. Otherwise there was no changing the attributes. DAI requires the gamer to select different skills that add to the attributes.
The stat allocation BG offered at the beginning of the game had a deep impact in gameplay flow. In DA:I you play precisely by changing those attributes with items and crafting; the gameplay is radically different. If anything this is, again, a difference.
Healing of any kind was limited in terms of spells and potions. No regenerating health.
No regenerating health, no, but many ways to heal your characters during combat by magic. In fact, healing magic palyed a huge role in a class "roleplaying" and could impact deeply the way the game was played. DA:I has only potions.
The trio of Tank (warrior), Mage and rogue( thief etc) have been around since the beginning of roleplaying games. In fact the Fantasy Trip by Metagaming only had two classes fighter and mage.
The way those roles are handled in Inquistion have little to do with the way Bioware tend to devise those clases in the past. The only class that still works, more or less like the old role, is the warrior-tank. Both the thief and the mage have different roles that clearly diverge from their late cousins. Thieves left diversity for damage dealing; mages left damage dealing for "crowd control" roles. The way those new roles are handled are much more similar to the gameplay changes late rpg gaming added to viodegames.