1) The center "control link" functions as a sub-frame brace and sub-frame mount. You can modify (replace) this brace for the +3 points under rule 5.3.F.4)
Add or modify other chassis stiffening devices or fabricated parts (such as lower strut braces or lower arm braces (with greater than two attachment points), subframe connectors, subframe braces, subframe mounts/bushings, etc) +3

Slotting the chassis bolt holes for this link would have the same effect, so would take the same +3 point assessment. It would not be considered an alteration of suspension mounting points, but would be, as stated above, considered a modification of a subframe mount. If this +3 points assessment is taken, then the other aspects of this rule can also be taken advantage of (more chassis stiffening devices, etc).

2) The "outside" links that connect the subframe to the trailing arms are considered either part of the subframe suspension mounting points, or are considered part of the trailing arms, whichever will be to the benefit of the competitor. Modifying or replacing them will result in either a +6 point assessment for relocation of suspension mounting points (5.3.E.17), or a +4 point assessment for control arm modification (5.3.E.9). If there are spherical joints involved in the upgrade, then the additional +3 point assessment under rule 5.3.E.24) applies. If the competitor is already taking points for either 5.3.E.17) or 5.3.E.9) for other modifications, then there would be no additional assessment for replacing these links. If neither of those assessments is already taken, then replacing these links would result in the lower +4 point assessment for control arm modification (5.3.E.9). As well, all control arms on the vehicle could them be modified without additional assessment.

3) Slotting of the bolt holes in the trailing arm that the "outside" links use to connect the trailing arms to the subframe are permitted under the No-Points assessment within rule 5.3.E.9)--with or without the use of eccentric bolts or bushings.