There is no concept of grappling in 4e.

The concept is replaced with the grab action which inflicts the grabbed condition. Which is defined thusly:

• The creature is immobilized.
• Maintaining this condition on the creature occupies whatever appendage, object, or effect the grabber used to initiate the grab.
• This condition ends immediately on the creature if the grabber is subjected to an effect that prevents it from taking actions, or if the creature ends up outside the range of the grabbing power or effect.

Breaking a grab is accomplished by spending a move action to attempt to escape, being pushed pulled or slid out of reach or by teleporting out of the grab. Escape attempts vs monsters are either set by a DC (can be different depending on whether athletics or acrobatics are used to escape), or by the monster's defenses (Fortitude for Athletics, Reflex for Acrobatics). When a PC grabs there is no DC and the character's defenses are used.

To update this to actually answer the question as now posed:

The basic action to grab someone is a standard action in which you make a strength attack against your enemy's Reflex. You are required to have a freehand, and your enemy cannot be more than one size larger than you. If you hit then you are grabbing your enemy. You may sustain this action with a minor and it may be sustained until it is escaped, you choose to release it as a free action, or you are rendered incapable of taking opportunity actions (dazed, stunned, unconscious, surprised, etc) Or you move away from the creature you are grabbing.

There are a few more rules related to the grabbed condition, but this is most of the stuff you need for play.

Yes you can use them, but you would have to make a concentration check or lose the usage.

According to the SRD on SLA:

A spell-like ability has no verbal, somatic, or material component, nor does it require a focus or have an XP cost. The user activates it mentally. Armor never affects a spell-like ability’s use, even if the ability resembles an arcane spell with a somatic component.

Using a spell-like ability while threatened provokes attacks of opportunity. It is possible to make a Concentration check to use a spell-like ability defensively and avoid provoking an attack of opportunity. A spell-like ability can be disrupted just as a spell can be. Spell-like abilities are subject to spell resistance and to being dispelled by dispel magic. They do not function in areas where magic is suppressed or negated.

And then under their section for Grappling:

You can attempt to cast a spell while grappling or even while pinned (see below), provided its casting time is no more than 1 standard action, it has no somatic component, and you have in hand any material components or focuses you might need. Any spell that requires precise and careful action is impossible to cast while grappling or being pinned. If the spell is one that you can cast while grappling, you must make a Concentration check (DC 20 + spell level) or lose the spell. You don’t have to make a successful grapple check to cast the spell.